In this paper, we present a novel face image validation system. The purpose of the system is to evaluate quality of face images for identification documents and to detect face images that do not satisfy the image quality requirements. To determine image quality the system first performs face detection in order to find facial features and determine image background. The system consists of seventeen separate tests. Each test checks one quality aspect of the face or of the whole image and compares it to the requirements of International Civil Aviation Organization (ICAO) proposals for machine readable travel documents. The requirements are designed to ensure good conditions for automatic face recognition. The tests are organized in a hierarchical way so the low-level tests are executed first and the high-level tests are executed last. The result of a test is a fuzzy value representing a measure of the image quality. Each test has a set of parameters that can be tuned to produce desired performance of the test. Initial testing of the system has been performed on the set of 190 face images and has demonstrated the feasibility of the method.