ABSTRACT This study aim to substantiate the effect of entrepreneurial training on Micro and Small entities (MSEs) in Nyamagana district, Mwanza. In this study independent variable were SMEs whose owners attended entrepreneurial training and those who never attended entrepreneurial training. Dependent variables are performance of these MSEs whereby the study focused on gross sales, return on equity and employment level between the two groups as performance indicators. The dimensions of the entrepreneurial training adopted on the study are pro activeness, innovativeness and record keeping. MSEs in this study are defined in terms of number of employees employed and level of capital invested in the business. This study focused on the Micro and Small enterprises which have 0 to 49 employees and with capital limitation up to 200million. This study covered 120 respondents of whom 60 respondents were SMEs with entrepreneurial training and the other 60 are the MSEs without training. This study adopted descriptive survey design as research methodology. The population of the study was 11,500 SMEs who are located at Nyamagana district. Purposive sampling technique was used to select the sample from the population. Concept of standard deviation as the measure of dispersion among the two groups was used to come up with the final conclusion. Findings revealed that MSEs with entrepreneurial training have higher performance compared to the MSEs whose owner never attended any entrepreneurial training. Results further indicate that SMEs owners do not support the idea that obtaining entrepreneurial training is the guarantee for the individual to be successful in the business. Study found that the barrier for SMEs to be successful is not only lack of entrepreneurial training, there are a number of factors that hinder SMEs good performance, these factors are like, shortage of capital, high tax rate and higher interest rate that are offered by some of microfinance institutions. The study recommends to MSEs owners taking more initiative and being proactive, innovative and maintains their records properly, this leads to a good business performance. The recommendation was also offered to business consultants, government institutions and policy makers for designing their training so as to suit the needs of the SMEs rather than providing entrepreneurial training in general basis