diff --git a/include/ecrt.h b/include/ecrt.h
index 962aa06a..9ba6f2cc 100644
--- a/include/ecrt.h
+++ b/include/ecrt.h
@@ -672,6 +672,18 @@ uint8_t *ecrt_sdo_request_data(
         ec_sdo_request_t *req /**< Sdo request. */
         );
 
+/** Returns the current Sdo data size.
+ *
+ * When the Sdo request is created, the data size is set to the size of the
+ * reserved memory. After a read operation the size is set to the size of the
+ * read data. The size is not modified in any other situation.
+ *
+ * \return Sdo data size in bytes.
+ */
+size_t ecrt_sdo_request_data_size(
+        const ec_sdo_request_t *req /**< Sdo request. */
+        );
+
 /** Get the current state of the Sdo request.
  *
  * \return Request state.
diff --git a/master/sdo_request.c b/master/sdo_request.c
index 840a0a44..becda748 100644
--- a/master/sdo_request.c
+++ b/master/sdo_request.c
@@ -177,6 +177,13 @@ uint8_t *ecrt_sdo_request_data(ec_sdo_request_t *req)
 
 /*****************************************************************************/
 
+size_t ecrt_sdo_request_data_size(const ec_sdo_request_t *req)
+{
+    return req->data_size;
+}
+
+/*****************************************************************************/
+
 ec_sdo_request_state_t ecrt_sdo_request_state(const ec_sdo_request_t *req)
 {
    return state_translation_table[req->state];
@@ -204,6 +211,7 @@ void ecrt_sdo_request_write(ec_sdo_request_t *req)
 
 EXPORT_SYMBOL(ecrt_sdo_request_timeout);
 EXPORT_SYMBOL(ecrt_sdo_request_data);
+EXPORT_SYMBOL(ecrt_sdo_request_data_size);
 EXPORT_SYMBOL(ecrt_sdo_request_state);
 EXPORT_SYMBOL(ecrt_sdo_request_read);
 EXPORT_SYMBOL(ecrt_sdo_request_write);