banking sector in India is facing challenging times with advent of globalization, privatization and liberalization in India. The banks are now facing challenges on cost reduction, innovative products and technology. Such as Net banking, mobile banking, ATMs and bill payments are the buzzwords that banks are using to attract the customers. Primarily this study aimed at the performances of ATM services of Indian Overseas Bank in Pudukkottai District. This is a case study approach. The customers of Indian Overseas Bank are selected on a simple random sampling method. Administering questionnaire to 320 respondents their perceptions are ascertained on various aspects of ATMs. Majority of the respondents from middle and higher income groups, degree and above qualification holders and male category expressed that factors like safety of the service, service rendered by the bank, nearness of the service, friends and relatives played a significant role in choosing this service. It is further ascertained that all other factors played supplementary role in selecting the service. With regard to overall satisfaction of the respondents about the ATM services it is ascertained that majority from middle and higher income groups and degree and above qualification holder expressed good and very good opinion about this service, however others expressed average performance which needs a separate study to tackle it properly.