Indigenous vegetables have historically played an important role in farming and consumption systems in Nigeria. Vegetable production like any other farming activity requires the use of inputs as efficiently as possible to optimize production. To identify the sources of efficiency among indigenous vegetable farmers, the stochastic frontier production function which incorporates a model for the technical efficiency effect was employed. Data from 100 indigenous vegetable (waterleaf) producers were obtained through two-stage sampling procedure with the aid of questionnaire. Using the maximum likelihood estimation analysis, asymptotic parameter estimates were evaluated to describe efficiency sources. Results revealed that the average resource use efficiency is 0.81 (81%) leaving an inefficiency gap of 0.19 (19%), indicating that about 19% higher production could be achieved using the same input mix. Land, labour, waterleaf cuttings were evaluated and identified as the most critical efficiency sources. Age, access to credit facilities, and market were identified as the most important explainers of inefficiency. To derive the benefits of economies of scale, indigenous waterleaf producers should increase their farm sizes devoted to waterleaf cultivation either by land consolidation or acquiring new farm plots.