The serial fusion of multiple biometric traits for personal identity verification has been poorly investigated so far. However, this approach exhibits some potential advantages, for example, the possibility of reducing the verification time for genuine users and the requested degree of user cooperation. Moreover, the use of multiple biometrics can discourage fraudulent attempts to deceive the system. In this paper, some preliminary results on a novel approach to multi-modal serial fusion are reported, with comparative results against the commonly used parallel fusion of face and fingerprint matchers.