This study focused on the analysis of factors influencing market participation decisions and the intensity of participation among smallholder maize farmers in Kaduna State, Nigeria. Primary data were collected from 600 randomly selected maize farmers in 2017. Result showed that April and December are the months which farmers sell large quantities of maize. Proportional transaction costs including individual farmer characteristics, private assets, public assets influenced the probability and intensity of market participation at various significant levels. Level of education and ownership of assets are critical in determining the intensity of market participation in the study area. The study concludes that variable transaction costs constitute one of the major binding constraints to maize market participation and commercialisation. The results suggest that policies aimed at developing rural infrastructure, improved access to assets, human and capital development and market information system could reduce transaction costs and enhance market participation and market supply.