Systems and methods for facilitating authentication for payment transactions using pattern-based time bound passwords. More specifically, techniques disclosed herein enable authentication of payment transactions performed by a user at a merchant terminal based on a pre-registered pattern provided by the user within a pre-defined time period limit. The pre-registered pattern drawn in the pre-defined time period is registered as a password for authenticating any payment transaction performed by the user using a payment card which is associated with an account of the user in an issuing bank. If the user provides the pre-registered pattern within the pre-defined time period limit, the payment transaction is authenticated. In another embodiment, such pattern-based time bound password is used as a second level authentication in which first level authentication is performed by a personal identification number.