Achieving state market policies depends partly on the extent to which changes in commodity prices are transmitted along supply chains. This paper examines the effect of the National Food Buffer Stock Company (NAFCO) on price transmission between white maize wholesale and retail markets in Kumasi, Ghana. The findings suggest that the speed of price transmission elasticity between the market pair is symmetrical pre-NAFCO, asymmetrical post-NAFCO, and asymmetrical over the entire price series. Decreases in prices in the wholesale market are transmitted more quickly to consumers, whilst price increases are passed through sluggishly by retailers. The before- and after- NAFCO regimes show that government intervention through the marketing activities of NAFCO has created an imperfect market environment for maize traders, resulting in asymmetry in the speed of price adjustment in the retail market.