This study evaluated the effect of mass drug administration (MDA) with praziquantel administered to school-aged children (SAC) combined with ‘track and treat’ of taeniosis cases on the prevalence of taeniosis. The study was conducted in 14 villages in Mbozi and Mbeya district, Tanzania. SAC received MDA with praziquantel in 2012 (both districts) and in 2013 (Mbozi only). Three cross-sectional population-based surveys were performed in 2012 (R0), 2013 (R1), and 2014 (R2). In each survey approximately 3,000 participants of all ages were tested using copro-antigen-ELISA. The prevalence of taeniosis was significantly higher (p=0.007) in Mbozi (3.0%) at R0 compared to Mbeya (1.5%). Twelve months after MDA in both districts (R1), the prevalence had dropped significantly in both Mbozi (2.0%, p=0.024) and in Mbeya (0.3%, p=0.004), but the significant difference between the districts persisted (p<0.001). Ten months after the second round of MDA in Mbozi (R2), the prevalence had dropped significantly again in Mbozi (0.8%, p<0.001), but had slightly increased in Mbeya (0.5%, p=0.051), with no difference between the two (p=0.51). Among SAC in Mbozi, infection significantly decreased at R1 (p=0.004, OR 0.12 CI: 0.02-0.41) and R2 (p=0.001, OR 0.24, CI: 0.09-0.53) when comparing to R0. In Mbeya infection decreased at R1 (p=0.013, OR 0.14, CI: 0.02-0.55), but no difference was found for R2 (p=0. 089), compared to R0 among SAC. This study showed that school-based MDA with praziquantel in combination with ‘track and treat’ of taeniosis cases reduced the prevalence of taeniosis, and that annual MDA was better than biennially MDA.