diff --git a/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java b/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java
index a056a68a01..7c973bf64e 100644
--- a/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java
+++ b/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -266,25 +266,25 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 	 */
 	private InputStream getBodyFromServletRequestParameters(HttpServletRequest request) throws IOException {
 		ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
-		Writer writer = new OutputStreamWriter(bos, FORM_CHARSET);
+		Charset charset = getFormCharset();
+		Writer writer = new OutputStreamWriter(bos, charset);
 
 		Map<String, String[]> form = request.getParameterMap();
-		for (Iterator<Map.Entry<String, String[]>> entryIterator = form.entrySet().iterator(); entryIterator.hasNext();) {
-			Map.Entry<String, String[]> entry = entryIterator.next();
-			String name = entry.getKey();
+		for (Iterator<Map.Entry<String, String[]>> entryItr = form.entrySet().iterator(); entryItr.hasNext();) {
+			Map.Entry<String, String[]> entry = entryItr.next();
 			List<String> values = Arrays.asList(entry.getValue());
-			for (Iterator<String> valueIterator = values.iterator(); valueIterator.hasNext();) {
-				String value = valueIterator.next();
-				writer.write(URLEncoder.encode(name, FORM_CHARSET));
+			for (Iterator<String> valueItr = values.iterator(); valueItr.hasNext();) {
+				String value = valueItr.next();
+				writer.write(URLEncoder.encode(entry.getKey(), charset));
 				if (value != null) {
 					writer.write('=');
-					writer.write(URLEncoder.encode(value, FORM_CHARSET));
-					if (valueIterator.hasNext()) {
+					writer.write(URLEncoder.encode(value, charset));
+					if (valueItr.hasNext()) {
 						writer.write('&');
 					}
 				}
 			}
-			if (entryIterator.hasNext()) {
+			if (entryItr.hasNext()) {
 				writer.append('&');
 			}
 		}
@@ -298,6 +298,19 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 		return new ByteArrayInputStream(bytes);
 	}
 
+	private Charset getFormCharset() {
+		try {
+			MediaType contentType = getHeaders().getContentType();
+			if (contentType != null && contentType.getCharset() != null) {
+				return contentType.getCharset();
+			}
+		}
+		catch (Exception ex) {
+			// ignore
+		}
+		return FORM_CHARSET;
+	}
+
 
 	private final class AttributesMap extends AbstractMap<String, Object> {
 
diff --git a/spring-web/src/test/java/org/springframework/http/server/ServletServerHttpRequestTests.java b/spring-web/src/test/java/org/springframework/http/server/ServletServerHttpRequestTests.java
index 4215d95fc1..a4113ac023 100644
--- a/spring-web/src/test/java/org/springframework/http/server/ServletServerHttpRequestTests.java
+++ b/spring-web/src/test/java/org/springframework/http/server/ServletServerHttpRequestTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.http.server;
 
 import java.io.IOException;
 import java.net.URI;
+import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
@@ -182,9 +183,7 @@ class ServletServerHttpRequestTests {
 		mockRequest.addParameter("name 2", "value 2+1", "value 2+2");
 		mockRequest.addParameter("name 3", (String) null);
 
-		byte[] result = FileCopyUtils.copyToByteArray(request.getBody());
-		byte[] content = "name+1=value+1&name+2=value+2%2B1&name+2=value+2%2B2&name+3".getBytes(StandardCharsets.UTF_8);
-		assertThat(result).as("Invalid content returned").isEqualTo(content);
+		assertFormContent("name+1=value+1&name+2=value+2%2B1&name+2=value+2%2B2&name+3");
 	}
 
 	@Test
@@ -192,9 +191,7 @@ class ServletServerHttpRequestTests {
 		mockRequest.setContentType("application/x-www-form-urlencoded; charset=UTF-8");
 		mockRequest.setMethod("POST");
 
-		byte[] result = FileCopyUtils.copyToByteArray(request.getBody());
-		byte[] content = "".getBytes(StandardCharsets.UTF_8);
-		assertThat(result).as("Invalid content returned").isEqualTo(content);
+		assertFormContent("");
 	}
 
 	@Test  // gh-31327
@@ -206,9 +203,7 @@ class ServletServerHttpRequestTests {
 		mockRequest.setContent("foo=bar".getBytes(StandardCharsets.UTF_8));
 		mockRequest.addHeader("Content-Length", 7);
 
-		byte[] result = FileCopyUtils.copyToByteArray(request.getBody());
-		byte[] content = "foo=bar".getBytes(StandardCharsets.UTF_8);
-		assertThat(result).as("Invalid content returned").isEqualTo(content);
+		assertFormContent("foo=bar");
 	}
 
 	@Test  // gh-32471
@@ -219,9 +214,25 @@ class ServletServerHttpRequestTests {
 		mockRequest.addParameter("lastName", "Test@er");
 		mockRequest.addHeader("Content-Length", 26);
 
+		int contentLength = assertFormContent("name=Test&lastName=Test%40er");
+		assertThat(request.getHeaders().getContentLength()).isEqualTo(contentLength);
+	}
+
+	@Test  // gh-34675
+	void getFormBodyWithNotUtf8Charset() throws IOException {
+		String charset = "windows-1251";
+		mockRequest.setContentType("application/x-www-form-urlencoded; charset=" + charset);
+		mockRequest.setMethod("POST");
+		mockRequest.addParameter("x", URLDecoder.decode("%e0%e0%e0", charset));
+
+		assertFormContent("x=%E0%E0%E0");
+	}
+
+	private int assertFormContent(String expected) throws IOException {
 		byte[] result = FileCopyUtils.copyToByteArray(request.getBody());
-		assertThat(result).isEqualTo("name=Test&lastName=Test%40er".getBytes(StandardCharsets.UTF_8));
-		assertThat(request.getHeaders().getContentLength()).isEqualTo(result.length);
+		byte[] content = expected.getBytes(StandardCharsets.UTF_8);
+		assertThat(result).as("Invalid content returned").isEqualTo(content);
+		return result.length;
 	}
 
 	@Test