Abstract: The common bean (Phaseolus vulgaris L.) is an important source of protein and minerals. It supplies all of the iron that humans require for metabolism and provides 25% of the daily requirements of magnesium and copper as well as 15% of potassium and zinc. The objective of this study was to determine the influence of the environment on iron and zinc concentrations and the performance of common bean genotypes. The experiments were conducted in the horticulture units at the Sokoine University of Agriculture (Morogoro) and Madiira-Arusha. A randomized, complete block design with three replications was used for 20 common bean genotypes. The leaves and seeds were collected at early flowering and at maturity and analyzed for iron and zinc concentrations, respectively. Several yield characteristics were measured, including the time required to reach 50% flowering and 85% maturity, the number of seeds to pod ratio, the number of pods to plant ratio, the 100 seed weight and the seed yield. Data analysis was performed using ANOVA and the mean was separated by Duncan’s multiple range test and correlation techniques. The tested genotypes exhibited significant (p<0.05) differences in iron and zinc concentrations in the leaves and seeds of plants from both locations, with plants from Madiira-Arusha having the largest differences. The leaves showed higher levels of iron and zinc than the seeds. We observed a correlation between the concentration of Fe and Zn in both leaves and seeds (r = 0.507*** and r = 0.495*, respectively). In addition, there were significant differences (p<0.05) in the yield characteristics between genotypes of plants from both locations. These results suggest that environmental effects play a role in genotype levels of Fe and Zn in both leaves and seeds.