Abstract: The general objective of this study was to determine the effect of organization culture on return on assets of large manufacturing firms in Kenya. The specific objective of this study was to determine the influence of organizational culture on return on assets of large manufacturing firms in Kenya. The study was a cross sectional survey targeting 102 large manufacturing firms and the response rate was from 94 firms. The data was analyzed using Statistical Package for Social Sciences. Null hypothesis was tested and results indicated that organizational culture had influence on return on assets. The study was limited in that change of variables of study was not monitored or observed over time as would be the case with longitudinal studies.