A DISSERTATION SUBMITED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURAL ECONOMICS OF THE SOKOINE UNIVERSITY OF AGRICULTURE. MOROGORO, TANZANIA.Sesame is among one of important economic crop for smallholder farmers and other actors involved in value chain. However, smallholder farmers have not fully benefited due to fragmented market and unimproved production. This study was conducted to assess the profitability of sesame actors along the value chain in Masasi District. The specific objectives were to identify the structure and functioning of the value chain; to determine the gross margin received by different actors along Sesame value chain and to determine the factors and their effects on the profitability along the sesame value chain in Masasi District. A survey of 126 randomly selected sesame farmers and 20 sesame traders was undertaken in the study area. Both qualitative and quantitative methods of data analysis were employed. Gross margin analysis was employed to determine the gross margin received by actors along the value chain. The results show that the key actors of sesame value chain include input suppliers, farmers, traders, commission agents and exporters. The findings also show that, farmers had a gross margin of 323.64 TZS per kg, while traders had a gross margin of 581.57 TZS per kg which was relatively higher than that of farmers. The major determinant factors for profitability of smallholder sesame producers were estimated by ordinary least square regression. The finding shows that the farmers’ gross margin was influenced by household education level, household age, market information and extension services. To increase farmer’s gross margin, the study recommends improving availability and accessibility of the market information network, farmers training, intensification of land utilization and value addition activity of sesame.