Index: src/ooxml/testcases/org/apache/poi/xwpf/usermodel/TestXWPFSDT.java
===================================================================
--- src/ooxml/testcases/org/apache/poi/xwpf/usermodel/TestXWPFSDT.java	(revision 1879153)
+++ src/ooxml/testcases/org/apache/poi/xwpf/usermodel/TestXWPFSDT.java	(working copy)
@@ -29,6 +29,17 @@
 import org.junit.Test;
 
 public final class TestXWPFSDT {
+ 
+    /**
+     * Test text extraction from nested SDTs
+     */
+    @Test
+    public void testNestedSDTs() throws Exception {
+        try (XWPFDocument doc = XWPFTestDataSamples.openSampleDocument("Bug64561.docx")) {
+            XWPFAbstractSDT sdt = extractAllSDTs(doc).get(0);
+            assertEquals("extracted text", "Subject", sdt.getContent().getText());
+        }
+    }
 
     /**
      * Test simple tag and title extraction from SDT
Index: src/ooxml/java/org/apache/poi/xwpf/usermodel/XWPFSDTContent.java
===================================================================
--- src/ooxml/java/org/apache/poi/xwpf/usermodel/XWPFSDTContent.java	(revision 1879153)
+++ src/ooxml/java/org/apache/poi/xwpf/usermodel/XWPFSDTContent.java	(working copy)
@@ -26,6 +26,7 @@
 import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTSdtBlock;
 import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTSdtContentBlock;
 import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTSdtContentRun;
+import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTSdtRun;
 import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTTbl;
 
 /**
@@ -50,11 +51,19 @@
         if (sdtRun == null) {
             return;
         }
-        for (CTR ctr : sdtRun.getRArray()) {
-            XWPFRun run = new XWPFRun(ctr, parent);
-            // runs.add(run);
-            bodyElements.add(run);
+        XmlCursor cursor = sdtRun.newCursor();
+        cursor.selectPath("./*");
+        while (cursor.toNextSelection()) {
+            XmlObject o = cursor.getObject();
+            if (o instanceof CTR) {
+                XWPFRun run = new XWPFRun((CTR) o, parent);
+                bodyElements.add(run);
+            } else if (o instanceof CTSdtRun) {
+                XWPFSDT c = new XWPFSDT(((CTSdtRun) o), part);
+                bodyElements.add(c);
+            }
         }
+        cursor.dispose();
     }
 
     public XWPFSDTContent(CTSdtContentBlock block, IBody part, IRunBody parent) {