$re = '/<Error>.*?<\/Error>/s';
$str = '<ET>read input: 1.629ms</ET>
<ET>There were 3 errors:
<Error>
<ErrorId>AllConditionsTrue</ErrorId>
<MetaData>
<Entry>
<Key>Balance Due</Key>
<Value>1500.99</Value>
</Entry>
</MetaData>
</Error>
<Error>
<ErrorId>Opposite</ErrorId>
<MetaData>
<Entry>
<Key>Node</Key>
</Entry>
</MetaData>
</Error>
<Error>
<ErrorId>minInclusive</ErrorId>
<MetaData>
<Entry>
<Key>Description</Key>
<Value>Wages Amount</Value>
</Entry>
</MetaData>
</Error>
: 0.027ms</ET>
<ET>convert: 319.414ms</ET>
<FORM id="123"/>
<DATA size="11920"/>
<ERROR code="0"/>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php