Smallholder farmers account for over 90 per cent of domestic rice production in Tanzania. Their participation in markets provides opportunities for growth through income and employment. However, their ability to participate is hampered by personal, household and institutional constraints. We adopt the double hurdle model to explore determinants of market participation by rice farmers using data collected from selected rice growing regions in Tanzania. The decision to participate in the market is affected by the cropped area, yield, distance to the market and type of variety grown. Besides these factors, the quantity marketed is affected by the existence of a market within the village. There is need for labour-saving technologies for area expansion and yield improvement.