This study was conducted in three wards of Kilosa District (i.e. Rudewa, Chanzuru and Mabwerebwere) to assess the effects of land tenure and farm fragmentation in the district. A sample of 90 households was selected for the study. Thirty households were selected from each ward. The general objective of the study was to assess the existing land tenure systems and farm fragmentation and their effects on agricultural productivity. The specific objectives were to identify the existing land tenure systems in the study area, to assess factors causing farm fragmentation and to assess the effects of farm fragmentation on agricultural productivity. Linear regression and correlation techniques were used to analyse the factors causing farm fragmentation and correlation analysis was used to assess the relationship between farm fragmentation and agricultural productivity. Customary land tenure (78%) was the most prevalent type of tenure system in the study area. The regression analysis indicates that farm fragmentation is greatly influenced by household size and education level of the heads of household and was statistically significant at P < 0.01 and the distance from homestead at P < 0.05. The results from correlation analysis indicate that that public land and customary tenure systems are positively associated with the level of farm fragmentation at P < 0.1 and 0.01 respectively. Furthermore, it was observed that age of the heads of household and the distance from homestead are positively associated and statistically significant at P < 0.1 and P < 0.01 levels respectively. From the study results, it is recommended that policy makers should intervene by reframing land policies in order to provide land security which will facilitate land use and increase agricultural productivity. It is also recommended that government intervention in land administration is of crucial importance to improveiii lad uses which allocate rights in land use as well as land-use regulation where by land-use planning and enforcement and the adjudication of land use conflicts are controlled.Ministry of Agriculture Food Security and Cooperatives (MAFCs)