diff --git a/README.md b/README.md
index cdade9a..20984b0 100644
--- a/README.md
+++ b/README.md
@@ -101,7 +101,8 @@ This migration will move the `id`, `email` and `name` fields from the the `users
 ### Source data validation
 
 You can use UXDM to validate the source data. If validation fails part way through a migration, the migration will 
-halt and a `ValidationException` will be thrown.
+halt and a `ValidationException` will be thrown. However, if `->validateBeforeMigrating()` is called, all data rows
+will be preemptively validated before the migration begins.
 
 The code below shows how to validate various fields.
 
@@ -119,6 +120,7 @@ $migrator->setSource($pdoSource)
             'email' => [new Required(), new IsString(), new IsEmail()],
             'name' => [new Required(), new IsString()],
          ])
+      // ->validateBeforeMigrating()
          ->setKeyFields(['id'])
          ->withProgressBar()
          ->migrate();
diff --git a/src/Objects/DataRow.php b/src/Objects/DataRow.php
index 7dca418..06866bb 100755
--- a/src/Objects/DataRow.php
+++ b/src/Objects/DataRow.php
@@ -73,7 +73,7 @@ public function prepare(array $validationRules, array $keyFields, array $fieldMa
         }
     }
 
-    private function validate(array $validationRules)
+    public function validate(array $validationRules)
     {
         if (!$this->dataItems) {
             throw new NoDataItemsInDataRowException('Data row contains no data items. The specified source may be producing an invalid data row.');
@@ -82,9 +82,7 @@ private function validate(array $validationRules)
         if ($validationRules) {
             $validator = new Validator($this->toArray(), $validationRules);
             if ($validator->fails()) {
-                $messages = print_r($validator->messages(), true);
-
-                throw new ValidationException($messages);
+                throw new ValidationException($validator->messages(), $this);
             }
         }
     }
diff --git a/src/Objects/Exceptions/ValidationException.php b/src/Objects/Exceptions/ValidationException.php
index 8aaabb8..b762edc 100644
--- a/src/Objects/Exceptions/ValidationException.php
+++ b/src/Objects/Exceptions/ValidationException.php
@@ -2,8 +2,39 @@
 
 namespace DivineOmega\uxdm\Objects\Exceptions;
 
+use DivineOmega\uxdm\Objects\DataRow;
 use Exception;
 
 class ValidationException extends Exception
 {
+    private $validationMessages;
+    private $dataRow;
+
+    public function __construct(array $validationMessages, DataRow $dataRow)
+    {
+        $this->validationMessages = $validationMessages;
+        $this->dataRow = $dataRow;
+
+        parent::__construct($this->buildExceptionMessage());
+    }
+
+    private function buildExceptionMessage(): string
+    {
+        $message = 'Validation exception: '.PHP_EOL;
+        $message .= print_r($this->validationMessages, true).PHP_EOL;
+        $message .= 'Data row: '.PHP_EOL;
+        $message .= print_r($this->dataRow->toArray(), true.PHP_EOL);
+
+        return $message;
+    }
+
+    public function getValidationMessages(): array
+    {
+        return $this->validationMessages;
+    }
+
+    public function getDataRow(): DataRow
+    {
+        return $this->dataRow;
+    }
 }
diff --git a/src/Objects/Migrator.php b/src/Objects/Migrator.php
index cdc3a1d..4122207 100644
--- a/src/Objects/Migrator.php
+++ b/src/Objects/Migrator.php
@@ -28,6 +28,8 @@ class Migrator
     private $sourceCacheKey;
     private $sourceCacheExpiresAfter;
     private $showProgressBar = false;
+    private $validateBeforeMigrating = false;
+    private $progressBar = null;
 
     /**
      * Set the source object to migrate data from.
@@ -257,6 +259,18 @@ public function withProgressBar()
         return $this;
     }
 
+    /**
+     * Enables validation of all data rows before the migration begins.
+     *
+     * @return $this
+     */
+    public function validateBeforeMigrating()
+    {
+        $this->validateBeforeMigrating = true;
+
+        return $this;
+    }
+
     /**
      * Retrieves one page of data rows from the source.
      *
@@ -337,6 +351,33 @@ public function migrate(): void
     {
         $this->sanityCheck();
 
+        if ($this->validateBeforeMigrating) {
+            if ($this->showProgressBar) {
+                $this->progressBar = new ProgressBar();
+                $this->progressBar->setMessage('Validating...');
+                $this->progressBar->setMaxProgress($this->source->countPages() * count($this->destinationContainers));
+                $this->progressBar->display();
+            }
+
+            for ($page = 1; $page < PHP_INT_MAX; $page++) {
+                $dataRows = $this->getSourceDataRows($page);
+
+                if (!$dataRows) {
+                    break;
+                }
+
+                foreach ($dataRows as $key => $dataRow) {
+                    $dataRow->validate();
+                }
+
+                $this->advanceProgressBar();
+            }
+
+            if ($this->showProgressBar) {
+                $this->progressBar->complete();
+            }
+        }
+
         if ($this->showProgressBar) {
             $progressBar = new ProgressBar();
             $progressBar->setMaxProgress($this->source->countPages() * count($this->destinationContainers));