This study was done in Kabale and Mbale districts of Uganda for the two potato growing seasons of 2011/2012. It sought to determine factors that hinder smallholder farmers’ level of participation in the potato market in addition to those that influence their decisions to participate in the potato market. It also aimed at developing potato farmer typologies basing on levels of market participation. Data from a survey of 200 potato farmers selected from Kabale and Mbale using a multi-stage sampling process was collected and analysed. Two econometric models were employed in the analysis. 1) An ordered probit model and descriptive statistics were used to characterise potato farmers as net sellers, net buyers and autarkic and used to explain factors that lead to such farmer behaviour 2) A twostage selectivity model similar to a Heckman was used in determining factors that influence farmers’ decisions to participate in the potato market and factors that determine the level of participation. The study results indicated that farmer’s marketing experience, garden size, distance to the nearest village market, road condition to market and possession of a mobile phone positively influenced potato farmers’ decision to be autarkic other than net buyers and net sellers other than autarkic ceteris paribus. The two-step Heckman results on the other hand revealed that condition of roads from villages to potato markets as well as age of the farmer positively and significantly influenced decisions to participate in markets while size of land owned influenced potato volumes sold in the market.