The common bean (Phaseolus vulgaris L.) is one of the most widely cultivated legume crops in the world because of its nutritional importance. In Guerrero, Mexico, it has been considered a subsistence crop, cultivated by local communities mainly for their own consumption. However, the specific varieties conserved in situ remain largely undocumented. This study characterizes the agrobiodiversity of common bean and examines variation in three seed sources: landrace seed, commercial seed [local markets], and seed from wild populations. In addition, the study seeks to document cultural practices associated with bean cultivation in the region. Between 2021 and2023, seed collections were carried out at local markets, with farmers, and from wild populations. Interviews were conducted with farmers and merchants. Seeds were grown under control conditions, and 22 morphological, phenological, floral traits, and yield-related variables were measured. The relative contribution of each seed source to the total variation was estimated. The study identified 11 landraces and four wild populations, revealing two genetic reservoirs: landraces/commercial seed and wild seed. Farmers maintain more agrobiodiversity than what is traded in local markets, although local markets act as hubs for seed distribution. Cultural practices play a crucial role in maintaining and generating local adaptations, thereby sustaining the agrobiodiversity of common beans in this region.