Watermelon [Citrullus lanatus (Thunb.)] marketing efficient distribution is needed to maximize economic returns to marketers and consumers. An economic analysis of watermelon marketing was done in Lagos state, Nigeria, between January and February 2018. Data were collected using a questionnaire employed to collect information from 56 marketers in the study area. Half of the marketers used urban markets as points of sale and watermelon were supplied weekly. Watermelon marketing was profitable. The major constraint encountered by marketers was their inability to access credit. Regardless of level of education sufficient market information enhanced economic returns of watermelon marketers.