Purpose – The purpose of this paper is to examine the nature of interactive effect of competition and corporate governance on productivity growth of firms in Nigeria. Studies that have considered this issue were mainly from developed countries possessing strong institutions as against those of developing countries like Nigeria. Moreover, studies from Nigeria have focused exclusively on corporate governance and firm performance. The interaction effect of competition on corporate governance is yet to be addressed in the context of Nigeria. Design/methodology/approach – The study adopts the dynamic panel data analysis approach suggested by Arellano and Bond for productivity growth analysis. Data on 76 non-financial firms for 11 years beginning from 1997 were extracted from the financial statements of companies collected from the Nigerian Stock Exchange and subsequently analysed using General Methods of Moments (GMM). Findings – The results show that competition had a positive impact on productivity growth, however, its interaction effect with corporate governance had a substitute but not significant impact on productivity growth. When competition was interacted with an alternative corporate governance mechanism – bank – a positive and significant impact was, however, observed which shows that competition and bank loans are complementary in stimulating productivity growth of firms in Nigeria. Research limitations/implications – The study could not be carried out beyond year 2007 owing to the exit of some firms after 2007 which could have reduced the sample size drastically. The findings emanating from this study suggests that government should focus much more on implementing competitive policies and bother less on writing corporate governance codes. Practical implications – The results demonstrate that corporate governance had no significant impact on productivity growth even when it was interacted with competition. However, competition on its own had a significant impact on productivity which means that Nigeria should concentrate more on building a competitive private sector, and in this regard, government should try and pursue policies that will foster competition and eliminate monopolistic tendencies. Once, there is effective competition, the corporate governance may be strengthened. However, the interactive effect of competition and bank loans was found with a positive and significant impact which indicates that banks as alternate corporate governance mechanism can only be effective if competition is strong. This goes to show that the financial sector may not be able to effectively and positively impact the real sector in Nigeria if the prevailing level of competition is low. In such a situation finance may not be channelled to projects that have long-run implications on sustainable growth and development. Social implications – Socially, if the environment for competition is not fostered in Nigeria, the country may face an uphill task in combating the problem of poverty through a private sector-led solution. Hence, there is a need for government to begin to formulate comprehensive competition policies that will ensure that resources are optimally utilized in Nigeria. Originality/value – In the context of Nigeria, this study is novel, the use of productivity growth as against firm financial performance is unique for Nigeria while the use of GMM method of analysis helps in reducing the effect of endogeneity inherent in corporate governance and performance of firms in Nigeria.