This research work, examined organizational citizenship behaviour and performance of money deposit banks in Nigeria. The objectives of the study included to: ascertain how selfless service affects service commitment of employees of Zenith Bank Branches in Enugu State, determine the extent to which courtesy affects quality of service of employees of the selected Zenith Bank Branches in Enugu State, assess the effects of civic virtues on punctuality of the selected Zenith Banks in Enugu, Nigeria, and identify how probity affects customers complaints of selected Zenith Banks in Enugu, Nigeria. The research method adopted by the study was the survey method. The sources of data used were the primary and secondary sources of data. The population of the study was 200 while the sample size of 139 was determined using the Taro Yamane’s formula. The major instrument of data collection was questionnaire. The data collected were presented in tables using frequencies and percentages and analyzed using the five point Likert scale. The hypotheses were tested using the chi-square distribution formula. The findings included that selfless service has significant positive effect on the behaviour of employees of Zenith Bank Nig. Plc, courtesy, to a large extent has a significant positive effect on the quality of service of employees of Zenith Bank Nig. Plc, civic virtues have significant positive effect on punctuality of the workers of Zenith Bank Nig. Plc and probity has significant positive effect on complaint of the customers of Zenith Bank Nig. Plc. The study concluded that organizational citizenship behaviour has a significant positive effect on the performance of money deposit banks in Nigeria and it was recommended that management of money deposit banks should encourage their workers to adopt selfless service in their day-to-day activities by giving them orientation on the need for such service, management of money deposit banks should equally encourage their workers to adopt courtesy by letting them know its importance in attracting customers for the organization, civic virtues should be encouraged by the management of money deposit banks through adequate orientation and the management of money deposit banks should encouraged probity among their workers.