The study was conducted in order to assess performance in revenue collection from fresh water fishes at Nyamagana Municipal Council. Specifically the study aimed at identifying sources of revenue from fishery sub sector at the Municipality; determining revenue collection gap between 2000 and 2010; as well as determining administrative factors that influence revenue collection performance and assessing extent sub sectoral factors influence revenue collection in the fishery sub sector. The study used both primary and secondary data. Primary data were collected using structured questionnaires with 120 randomly selected fish traders and fisheries officers. The data were analyzed using SPSS and MS-Excel. The collection gap found was 1.09 billion TZS with a T-test of 0.002 at five percent level of significance. Multiple regression model was used to determine administrative (revenue payers identification, revenue payers assessment, collection procedures as well as revenue payers sensitization) factors that influence revenue collection performance. It was found that both administrative factors are significant at five percent level of significance. Adjusted R2 was 0.60 (indicating the relationship between dependent and independent variables by 60%). F-value is positive (35.10357) and significant at. All coefficients indicate positive relationship between variables (revenue payers’ identification (0.20), revenue payers’ assessment (0.12), revenue collection procedures (0.12) and sensitization (0.12). Identification of revenue payers’ has the highest contribution (p=0.000), followed by revenue payers’ assessment (p=0.01), sensitization of revenue payers (p=0.04) and last revenue collection procedure (p=0.024) both at five percent level of significance. Also sub sectoral factors influence revenue collection including illegal fishing (20%), corruption (16.7%), good governance and management of natural resources (16.7%) was assessed. The study recommends policy action on revenue administration to be strengthened in order to improve revenue collection capacity as well as curbing illegal fishing and corruption in the fishery sub sector.Belgian Embassy through Belgian Technical Cooperation (BTC)