| 2003 | The Fifteenth Annual General Meeting was held at Galle Face Hotel, Colombo 3. |
| 2003 | Hosted SEARCC Ex-co meeting and SEARCC International School's Software Competition in Colombo. |
| 2003 | Gifts ICT Books to Colombo Public Library |
| 2003 | Hosted National Schools Software Competition. |
| 2003 | Launch 10 public lectures during the year |
| 2003 | 22nd National IT Conference |
| 2003 | Awarding of honorary fellowships to distinguished members of Society Dr. Abhaya Samarath Induruwa, Dr Bandusena Ranasinghe and Ms. Sunethra Nayeni Fernando. |
| 2003 | Launching the member subscription payment though Internet. |
| 2003 | Introducing the membership card |
| 2003 | Announce the member benefits programme to all the Members and Associate Members of the Society |
| 2002 | CSSL was appointed as the Accreditation Agent for ICDL in Sri Lanka. |
| 2002 | Appointed Mr. Y.R.Karunaratne as the new Secretary General of SEARCC and the SEARCC Secretariat has established in Sri Lanka and facilitated by CSSL. |
| 2001 | 25th Anniversary Celebrations of the CSSL |
| 2001 | Awarding of Honorary Fellowships to two distinguished members of the Society Mr. R.B.Ekanayake and Mr.Y.R.Karunaratne. |
| 2001 | Unveiling of portraits of the immediate past Presidents Mr. T.L.Chandranath |
| 2001 | The Executive Council meeting of SEARCC was held in Colombo. |
| 2000 | Unveiling of portraits of distinguished past Presidents Mr. R.B.Ekanayake and Mr. Y.R.Karunaratne who laid a firm foundation for CSSL. |
| 2000 | Moving into the new office premises |
| 1999 | Launching CSSL web site "www.cssl.lk" |
| 1995 | Hosting the first International IT Conference SEARCC '95 in Colombo |
| 1995 | Winning the SEARCC International Software Competition F.C.Kohli challenge Trophy |
| 1992 | International Olympiad in Bonn, Germany in Association with CINTEC & ACTOS |
| 1990 | International Software Competition in Manila & Singapore |
| 1990 | Launching of National Schools Examinations in Sri Lanka Software Competition |
| 1990 | Introducing Australian Computer Sri Lanka Society |
| 1989 | Joining the Organisation of Professional Associations |
| 1989 | Reciprocal agreement with Australian Computer Society |
| 1986 | Joining the South East Asia Regional Computer Confederation |
| 1986 | Incorporation of CSSL under the companies Act |
| 1985 | Introducing British Computer Society Examinations in Sri Lanka |
| 1976 | Inauguration of Computer Society of Sri Lanka |
