This study investigated farmer characteristics, private assets, public assets and transaction cost variables influencing the probability and intensity of participating in the market by smallholder maize farmers in the Upper West Region of Ghana. The Household Commercialisation Index was used to estimate the level of market participation and the Double Hurdle Model was used to estimate the factors influencing both market participation and intensity of participation. The results indicated that about twenty-four percent of maize is sold in the region within a production year which implies low commercialisation index. Specific farmer characteristics, private assets, public assets and transaction cost variables significantly influenced the probability and intensity of market participation behaviour in the region. The study concludes that maize is produced as a staple for household consumption. The study recommends that government through the Ministry of Food and Agriculture should institute productivity enhancing measures to increase the productivity of maize as well as establish rural finance schemes to address the credit needs of smallholders.