This validator allows you to validate if a given string conforms a defined regular expression. The following options are supported for Zend_Validate_Regex: pattern: Sets the regular expression pattern for this validator. Validation with regular expressions allows to have complicated validations being done without writing a own validator. The usage of regular expression is quite common and simple. Let's look at some examples: '/^Test/'); $validator->isValid("Test"); // returns true $validator->isValid("Testing"); // returns true $validator->isValid("Pest"); // returns false ]]> As you can see, the pattern has to be given using the same syntax as for preg_match(). For details about regular expressions take a look into PHP's manual about PCRE pattern syntax. It is also possible to set a different pattern afterwards by using setPattern() and to get the actual set pattern with getPattern(). '/^Test/'); $validator->setPattern('ing$/'); $validator->isValid("Test"); // returns false $validator->isValid("Testing"); // returns true $validator->isValid("Pest"); // returns false ]]>