This paper reports the findings of a study concerning the adoption of internet banking by investigating consumer adoption within the context of Sri Lankan banking services. The research framework was based on the extension to decomposed theory of planned behavior which mainly includes attitude (including innovation characteristics such as relative advantage, compatibility, complexity, trialability and risk), subjective norms, and perceived behavioral control to assess internet banking adoption behavior. Online questionnaire survey was conducted to gather the data and 108 complete responses were gathered from random banking customers who were internet users from Colombo and Gampaha district. Descriptive analysis was done to provide strength to the research study which showed that even though considerable people were aware about internet banking, most of them were resistance to adopt internet banking. Spearman’s rank correlation was used to examine relationship of eleven hypotheses with actual internet banking usage. Results revealed that attitudinal and perceived behavioral control factors rather than social influence (subjective norms) plays a significant role in influencing adoption of internet banking. In particular relative advantage, compatibility with values, internet skills, trialability, risk, confidence of using such services (self-efficacy), and technology support found to influence the adoption of internet banking. Conclusion of the research study implied that banks have to majorly influence the internet banking adoption through ‘pull strategies’.