The password-based door lock system is an electronic access control mechanism that eliminates the need for traditional physical keys. By utilizing a password input interface (keypad), the system ensures secure entry while providing high flexibility and ease of use. This paper presents a design and implementation of a password-based door lock system using the 8051 microcontroller. The system consists of a keypad for user input, an LCD to display feedback, and a motor to control the door lock mechanism. Upon entering a correct password, the door unlocks; incorrect attempts result in an alarm or time delay. This paper details the design, implementation, and testing of the system, demonstrating its effectiveness in securing homes, offices, and other premises.