Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control for doors forms a vital link in a security chain. The microcontroller based digital lock for Doors is an access control system that allows only authorized persons to access a restricted area. The system is fully controlled by the 8 bit microcontroller AT89S52 which has a 8Kbytes of ROM for the program memory. The password is stored in the EPROM so that we can change it at any time. The system has a Keypad by which the password can be entered through it. When they entered password equals with the password stored in the memory then the motor gets activated so that the door is opened. If we entered a wrong password a buzzer is switched on and error is indicated. The user is required to enter the code again after some delay.