DOMDocument::validate Validates the document based on its DTD &reftitle.description; public boolDOMDocument::validate Validates the document based on its DTD. You can also use the validateOnParse property of DOMDocument to make a DTD validation. &reftitle.parameters; &no.function.parameters; &reftitle.returnvalues; &return.success; If the document has no DTD attached, this method will return &false;. &reftitle.examples; load('book.xml'); if ($dom->validate()) { echo "This document is valid!\n"; } ?> ]]> You can also validate your XML file while loading it: validateOnParse = true; $dom->load('book.xml'); ?> ]]> &reftitle.seealso; DOMDocument::schemaValidate DOMDocument::schemaValidateSource DOMDocument::relaxNGValidate DOMDocument::relaxNGValidateSource