The purpose of the study was to determine the yield gap of brinjal with the causing factors and explore the relationship between the yield gap and the socioeconomic characteristics of the farmers. The study was conducted with a sample of 50 farmers randomly selected from five villages in Raghunathnagar union under Jhikargacha upazila of Jashore district using a structured interview schedule from February to March 2020. The yield gap was measured based on the differences between the achievable yield recorded at the particular study location and the average actual yield harvested by the farmers. The results revealed that the majority (76.0%) of farmers had a moderate yield gap (26-65.0% gap), while 14.0% had a low yield gap (up to 25.0% gap) and about 10% high yield gap (more than 65% gap). Inadequate amounts of different inputs used in brinjal production along with some socio-psychological-economic characteristics of farmers were the causes of the yield gap. For instance, 80% of farmers had a high gap in the application of Supreme- a locally popular insecticide for controlling fruit and shoot borer, in the case of pesticide application (74% and 76% of farmers had high gap in the application of Amister and Amagold) followed by 74% had high gap in TSP and Mop application, 76% had high gap in Urea application, 60% had high gap in Boron application, 72% had high gap in Gypsum application, almost 58% had medium to high gap in Cowdung application and 44% had high gap in irrigation application. The results of the correlation co-efficient ‘r’ also revealed that family size, farm size, extension contact, farming experience, knowledge, and level of inputs use were negatively significant with yield gap, while the problems they experienced in brinjal production had a positive significant relationship. The top five problems were: price hike of different inputs required for brinjal production, and poor selling price of products as it is maintained by business syndicates along with lack of proper knowledge about fertilizer management, heavy attack of insects and pests in the brinjal fields, insufficient extension services and lack of training of the farmers about the modern production method of brinjal.