A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Masters of Business Administration (Corporate management) – MBA (CM) of Mzumbe UniversityMicrofinance institutions (MFIs) generate or bridge the gap left by commercial banks in issuing microcredit to poor people, small businesses and micro entrepreneurs. The main objectives of MFIs include outreach to the poor, making positive impact and maintaining financial sustainability. The objectives are interrelated as for MFIs to fulfil the objective of outreach to poor population and making positive impact they should operate on a sustainable basis. The aim of the study was to determine the impact of staff training and financial regulations on financial sustainability of MFIs in Tanzania case of Morogoro municipality. The study followed a descriptive research design using a set of 42 observations from 14 MFIs over the period 2011-2013 out of the population of 116 MFIs in Morogoro municipal. Stratified random sampling technique was used to get the number of MFIs during the study. Two types of data were collected, primary and secondary by using questionnaires and documentation review respectively. Data was analysed using descriptive analysis, correlation analysis and multiple regression. The findings reveal that there is a positive statistically significant relationship between staff training and financial sustainability. The study also revealed that there is a negative statistically significant relationship between financial regulations and financial sustainability of MFIs in Tanzania. The study show that 76.1% of the variability in financial sustainability is due to variability of staff trainings and financial regulations meanwhile the remaining 23.1% was due to other variables which were not studied in the research. Financial regulation makes the strongest statistically significant unique contribution in explaining financial sustainability of MFIs in Tanzania compared to staff training.