Organizational culture is a system of meanings shared to various degrees in an organizational performance. Despite the attention paid to the importance of organizational culture in Nigerian deposit money banks, most studies have not provided consistent evidences. This is partially due to its complexity and the difficulties in defaming and measuring organizational culture. Therefore, this paper aims to examine the relationship between organizational culture and organizational performance of Nigerian deposit banks: evidence from zenith bank plc. In doing so, structured questionnaire which consisted of four parts of organizational culture dimensions, the study has its focus on organizational ulture specified as innovation and risk taking, attention to detail and staff orientation, while quality and innovation (IQ) and job performance (JP) represent firm performance to be tested along with firm’s size as the control variable, others are FS = Firm’s Size (as firm’s characteristic indicatorsthe results reveal that employees believe that their organization enjoys significant quality and innovation as well as a good competitive edge in the marketplace. Likewise, this finding confirms literature which suggests that organizational culture have influence on of which positively impact on organizational culture as well as the development quality and innovation of competitive advantage in the long run.