A rule based biometric user authentication method and system in a computer network environment is provided. Multiple authentication rules can exist in the computer network. For example, there may be a default system-wide rule, and a rule associated with a particular user trying to log in. There may be other rules such as one associated with a remote computer from which the user is logging in, one associated with a group to which the user belongs, or one associated with a system resource to which the user requires access such as an application program or a database of confidential information. An order of precedence among the rules is then established which is used to authenticate the user.