This paper presents an empirical investigation to detect important factors influencing on electronic banking adoption using factor analysis. The proposed study designed a questionnaire, distributed among 210 customers who were regular customers of four banks in city of Tehran, Iran named Saderat, Eghtesad Novin, Melli and Mellat. The questionnaire consists of 42 questions and since factor analysis is sensitive on skewness of data, we have decided to remove some of the questions and summarize it into 17 questions. Cronbach alpha was calculated as 0.80, which is well above the minimum acceptable limit and validates the results. The results of our survey indicate that four major factors including consistency, facilities, cost control and feasibility.