The Department of Computer Science was started in the year 1983. The Department offers B.Sc. (Computer Science) from 1983, MCA from 1984, M.Phil. and Ph.D. programmes from 2002. St. Joseph`s College was the first Arts and Science College to offer MCA in India and first to produce the PhD in Computer Science in the Bharathidasan University. There are 11 aided and 17 unaided staff members. Among five PhD holders, three staff members are guiding research scholars for Ph.D, 5 staff members are qualified NET/SET and 23 staff members are having M.Phil degree in Computer Science. The staff members of the Department serve as members of inspection committee of the Bharathidasan University for approval of Computer Courses, members of staff selection committee of other colleges, members of organizing committee of various conferences of international and national level and members of editorial board of research journals. In 2005 and 2007 a national level conference was organized. In 2014 an International Conference is to be held. The Department has produced 15 Ph.Ds and around 150 M.Phils. Seven minor research projects were completed, funded by UGC. Currently, one minor project funded by UGC and one major project funded by DST are under progress. To adhere to the motto of the Department "Professional Excellence", the Training and Placement Cell of the Department has helped to place 53 students in 2007, 2 in 2008, 9 in 2009, 23 in 2010 and 23 in 2011 in various MNCs. The companies like Asian Paints, Patni Computer Systems, Fulcrum Technologies, HCL, Infosys, Wipro Technologies, Satyam, TCS, Sutherland Global Services, iGate, Savvion, NetMagnus, Kumaran Systems and ISG Novasoft prefer to provide project cum placement to our students for their values and professional commitment.