diff --git a/src/main/java/picard/sam/CreateSequenceDictionary.java b/src/main/java/picard/sam/CreateSequenceDictionary.java
index 6aa587a79..90774a748 100644
--- a/src/main/java/picard/sam/CreateSequenceDictionary.java
+++ b/src/main/java/picard/sam/CreateSequenceDictionary.java
@@ -23,6 +23,7 @@
  */
 package picard.sam;
 
+import com.google.common.annotations.VisibleForTesting;
 import htsjdk.samtools.SAMSequenceDictionary;
 import htsjdk.samtools.SAMSequenceDictionaryCodec;
 import htsjdk.samtools.SAMSequenceRecord;
@@ -32,6 +33,7 @@
 import htsjdk.samtools.util.AsciiWriter;
 import htsjdk.samtools.util.CloseableIterator;
 import htsjdk.samtools.util.IOUtil;
+import htsjdk.samtools.util.Log;
 import htsjdk.samtools.util.Md5CalculatingOutputStream;
 import htsjdk.samtools.util.RuntimeIOException;
 import htsjdk.samtools.util.SortingCollection;
@@ -50,6 +52,7 @@
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 
 /**
@@ -79,11 +82,13 @@
             "<hr />";
     // The following attributes define the command-line arguments
 
+    private static final Log logger = Log.getInstance(CreateSequenceDictionary.class);
+
     @Option(doc = "Input reference fasta or fasta.gz", shortName = StandardOptionDefinitions.REFERENCE_SHORT_NAME)
     public File REFERENCE;
 
-    @Option(doc = "Output SAM or BAM file containing only the sequence dictionary",
-            shortName = StandardOptionDefinitions.OUTPUT_SHORT_NAME)
+    @Option(doc = "Output SAM file containing only the sequence dictionary. By default it will use the base name of the input reference with the .dict extension",
+            shortName = StandardOptionDefinitions.OUTPUT_SHORT_NAME, optional = true)
     public File OUTPUT;
 
     @Option(doc = "Put into AS field of sequence dictionary entry if supplied", optional = true)
@@ -146,9 +151,24 @@ public SAMSequenceDictionary makeSequenceDictionary(final File referenceFile) {
         if (URI == null) {
             URI = "file:" + REFERENCE.getAbsolutePath();
         }
+        if (OUTPUT == null) {
+            // TODO: use the htsjdk method implemented in https://github.com/samtools/htsjdk/pull/774
+            OUTPUT = getDefaultDictionaryForReferenceSequence(REFERENCE);
+            logger.info("Output dictionary will be written in ", OUTPUT);
+        }
         return null;
     }
 
+    // TODO: this method will be in htsjdk (https://github.com/samtools/htsjdk/pull/774)
+    @VisibleForTesting
+    static File getDefaultDictionaryForReferenceSequence(final File fastaFile) {
+        final String name = fastaFile.getName();
+        final String extension = ReferenceSequenceFileFactory.FASTA_EXTENSIONS.stream().filter(name::endsWith).findFirst()
+                .orElseGet(() -> {throw new IllegalArgumentException("File is not a supported reference file type: " + fastaFile.getAbsolutePath());});
+        final int extensionIndex = name.length() - extension.length();
+        return new File(fastaFile.getParentFile(), name.substring(0, extensionIndex) + IOUtil.DICT_FILE_EXTENSION);
+    }
+
     /**
      * Do the work after command line has been parsed.
      * RuntimeException may be thrown by this method, and are reported appropriately.
diff --git a/src/test/java/picard/sam/CreateSequenceDictionaryTest.java b/src/test/java/picard/sam/CreateSequenceDictionaryTest.java
index bb0821482..802714528 100644
--- a/src/test/java/picard/sam/CreateSequenceDictionaryTest.java
+++ b/src/test/java/picard/sam/CreateSequenceDictionaryTest.java
@@ -24,6 +24,7 @@
 package picard.sam;
 
 import org.testng.Assert;
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 import picard.cmdline.CommandLineProgramTest;
 import picard.PicardException;
@@ -47,6 +48,23 @@ public String getCommandLineProgramName() {
         return CreateSequenceDictionary.class.getSimpleName();
     }
 
+    @DataProvider
+    public Object[][] fastaNames() {
+        return new Object[][] {
+                {"break.fa", "break.dict"},
+                {"break.txt.txt", "break.txt.dict"},
+                {"break.fasta.fasta", "break.fasta.dict"},
+                {"break.fa.gz", "break.dict"},
+                {"break.txt.gz.txt.gz", "break.txt.gz.dict"},
+                {"break.fasta.gz.fasta.gz", "break.fasta.gz.dict"}
+        };
+    }
+
+    @Test(dataProvider = "fastaNames")
+    public void testGetDefaultDictionaryForReferenceSequence(final String fastaFile, final String expectedDict) throws Exception {
+        Assert.assertEquals(CreateSequenceDictionary.getDefaultDictionaryForReferenceSequence(new File(fastaFile)), new File(expectedDict));
+    }
+
     @Test
     public void testBasic() throws Exception {
         final File outputDict = File.createTempFile("CreateSequenceDictionaryTest.", ".dict");
@@ -61,6 +79,19 @@ public void testBasic() throws Exception {
     }
 
     @Test
+    public void testDefaultOutputFile() throws Exception {
+        final File expectedDict = new File(TEST_DATA_DIR + "/sam", "basic.dict");
+        expectedDict.deleteOnExit();
+        Assert.assertFalse(expectedDict.exists());
+        final String[] argv = {
+                "REFERENCE=" + BASIC_FASTA,
+                "TRUNCATE_NAMES_AT_WHITESPACE=false"
+        };
+        Assert.assertEquals(runPicardCommandLine(argv), 0);
+        Assert.assertTrue(expectedDict.exists());
+    }
+
+    @Test
     public void testForEquivalence() throws Exception {
         final File outputDict = File.createTempFile("CreateSequenceDictionaryTest.", ".dict");
         outputDict.delete();