Twenty-six landraces of black gram collected from Orissa, India were analysed for genetic diversity using amplified fragment length polymorphism (AFLP) markers. Seven primer combinations were used for AFLP analysis. The percentage polymorphism across the samples varied from 74.5 to 93%. The level of rare and common alleles contributing to the diversity in the sample was analysed using the Shannon–Weiner (SW) diversity index. The SW index revealed that three samples of the entire twenty-six contributed significantly to the overall diversity of the sample set. A dendrogram was constructed based on the UPGMA clustering method, which revealed three major clusters. A principal component analysis of the same dataset revealed similar results to that of the dendrogram, with the first principle component accounting for 58% of the total variation. The analysed samples formed five significant groups. Three samples were distinct in their clustering and remained separate from the other samples. Influence of soil pattern and topography in the genetic make up of the landraces was visible and seemed to contribute to the genetic distinctness of the landraces. This genetic diversity could well be utilized for future breeding work.