This study was carried out to estimate the level of diversity existing within some common bean landraces still cultivated in Nebrodi mountains, North-western area of Sicily. The multidisciplinary approach adopted to reach this goal involved the characterisation of collected material through morphological, biochemical and molecular marker analyses. The nutritional quality of seeds was also investigated in view of the proposition of the best landraces as niche products. Results showed that those bean landraces retain a considerable level of heterogeneity. The use of both biochemical and molecular markers showed that all landraces clustered into two main groups, corresponding to the Andean and Mesoamerican gene pools. Our results suggest that the best strategy for preserving the diversity of common bean from a restricted area such as Nebrodi mountains, necessitates of a deep knowledge of germplasm to avoid the loss of precious genetic resources or, on the contrary, the safeguard of populations genetically redundant.