Drought stress is a major production constraint to common bean and therefore development of drought adapted bean varieties is a key strategy to minimize crop failure and improve food security. Previous research indicated that the superior performance of bean genotypes under drought was associated with their ability to mobilize photosynthates to developing grain. The main objective of this work was to evaluate genotypic differences in physiological aspects of drought adaptation among promising bredlines. Two field trials were conducted at Palmira, Colombia. Both trials included 36 bred lines and germplasm accessions. Two levels of water supply (irrigated and rainfed) were applied. A 6 x 6 partially balanced lattice design with 3 replications was used. A number of plant attributes were measured at mid-podfilling. Under water stress conditions in the field, the seed yield of 36 genotypes ranged from 448 to 1268 kg/ha. Correlation coefficients between final grain yield and other shoot attributes indicated that greater seed yield under rainfed conditions was positively related to pod harvest index and negatively related with pod wall biomass proportion and seed N and P content. Results indicated that two accessions of P. acutifolius (G 40159 and G 40068) and two bred lines (RAB 650, SEA 23) were outstanding in their adaptation to water stress conditions and this was associated with their ability to mobilize photosynthates to developing grain and to utilize the acquired N and P more efficiently for grain production. Among the plant traits evaluated, pod harvest index, pod wall biomass proportion and seed P content were identified as useful traits to consider in the breeding program in addition to grain yield for identifying bean genotypes that are better adapted to drought. This work is partially supported from the funds of BMZ-GTZ, Germany (No. 2002.7860.6-001.00; Contract No. 81060499).