Smart Card Based Door Access System has two parts that is the door latch/ unlatch mechanism and the intelligence imparting unit that makes the system transparent to valid and authorized users and non accessible to others. The Door Access System is housed in SS casing and partially grouted in the door frame/ wall, for high mechanical strength and support. The Door Access System is a smart card based and comes with manual and automatic control of electronic lock. Smart Card Based Door Access System is provided with pass word changing facility.