The study compared the productivity of watermelon production for Fadama III Project support among beneficiaries and non-Beneficiaries in Misau Local Government Area, Bauchi State, Nigeria. A total of 140 watermelon farmers were randomly selected from the study area, consisting of 70 Fadama III project beneficiaries and 70 non-beneficiaries, respectively. Primary data were collected using questionnaires. The data were analyzed using descriptive statistics, farm budgeting and regression analysis. The result reveals that the net farm income earned by beneficiaries (N79, 972.80/ha) was higher than those of the non-beneficiaries (N43, 163.96). The returns on naira invested were equally higher for beneficiaries than non-beneficiaries'. Seed input was a significant fertilizer, labour, farm size, agro-chemicals and fuel significantly determined the output of watermelon in the farms. The efficiency ratio for seeds, agro-chemicals, fuel and farm size were utilized below economic optimum level, while labor, fertilizer were used above economic optimum by both beneficiaries and non-beneficiaries, respectively. The main constraints of watermelon production in both farms included pest and disease infestation, inadequate fertilizer, high costs of seeds. inadequate extension services and lack of credit facilities. The study therefore, recommended the provision of more extension agents, provision of fuel at affordable price, provision of credit facilities by the banks at reasonable interest rates, provision of farm inputs at lower prices and provision of permanent fencing materials to restricts domestic animals on free range from encroaching watermelon farms toward facilitating effective watermelon production.