Performance is a very broad concept and entails both financial and non-financial measures. The purpose of this study was to assess the relationship between organizational culture and Performance of Pharmaceutical Manufacturing firms in Kenya. The specific objectives of the study were to determine the relationship between organizational structure, reputation and firm’s performance. The findings of this study were valuable to the managers of the Pharmaceutical manufacturing sector, researchers and academicians in providing knowledge on organizational culture implementation on firm performance especially in the context of developing economies. The research used descriptive survey design. Data collected was both qualitative and quantitative. The target population comprised of managers in all the 19 Pharmaceutical manufacturing firms listed by the Pharmaceutical Society of Kenya (PSK, 2016). A sample of 209 was selected. This included one manager from each department who was identified as being directly related to strategy implementation. 19 firms and 209 mangers formed the sample size. The researcher used questionnaires to collect data. Once data was collected, it was coded and analyzed using SPSS version 21 where multiple regressions was used to show the relationship between independent and dependent variables of the study.