Current wave of Social Networking Sites (SNS) has become a part of peoples’ daily lives. This study investigates the role of Personal Innovativeness in Information Technology (PIIT), in acceptance of SNS. The theoretical perspective of Technological Acceptance Model (TAM) and PIIT were used to explain the relationships developed in the study. This research is descriptive in nature and is based on primary data collected through self-administered questionnaires, among a sample of 216 undergraduates in Sri Lanka. Findings reconfirmed the relationships in original TAM, enabling to use TAM in SNS context. Further, PIIT significantly predicts the Perceived Ease of Use (PEOU) of SNS. However, PIIT did not moderate the relationship between Perceived Usefulness (PU) and Intention to Use (IU) SNS. Theoretical and practical implications of these findings and directions for further research are discussed.