This study was prompted by the many challenges encountered in the management and utilization of the lake’s fisheries resources. The study was conducted at the four designated landing beaches around the lake. The aim was to assess the impact of co-management on Lake Naivasha fishery towards sustainable fisheries development. A mixed-method research design was used in the collection of the socio-economic data. A total of 633 respondents participated in the study. Of these, 28% were female and 72% were male. The majority (59%) were of the age group 20-34 years. The crew/fishermen were the majority at 47% followed by traders at 30%. Boat owners, net repairers and transporters comprised 7%, 3% and 4% respectively. Of those interviewed, 79% acknowledged that BMU has been successful, while the rest felt that the concept has failed. The study found that the impact of co-management on the lake’s fishery varied among the landing sites. Positive impacts of co-management were reported in all the beaches. Corruption and mismanagement of the resource were ranked highest as some of the negative impacts of comanagement of the fishery (42% and 22% respectively). Recommendations for effective co-management included, improvement of BMU management and coordination, development of beach infrastructure and training of BMU members (21%, 15% and 13%) respectively.