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Three trials were planted at CIAT, Colombia, with selected lines of red seeded beans (Phaseolus vulgarisL.), representing the best that has emerged from breeding of each growth habit, in order to study the relationship between growth habit and competitive ability with maize (Zea maysL.) when intercropped. Treatments included sole cropping without stakes, and with stakes that varied in height from 1 m to 2 m, and intercropping with short and tall maize cultivars. Highly significant interactions of bean lines by cropping systems were found. Correlations between yields of bean lines in sole cropping without stakes and intercropped were negative or zero, whereas correlations between sole cropping with stakes and intercropping were significant and positive. Internode length increased with growth habit, from bush to climbing types, and indeterminate types were stimulated to develop more main stem nodes either by the presence of a stake or a maize plant. Climbing types (Type IV) tended be later to flowering and maturity and were more competitive with the maize than bush types. Harvest index was reduced less in the Type IV lines when intercropped with maize than in the bush lines (Types I, II, and III). In a breeding program, selection in crosses among growth habits will tend towards bush types of beans when selected in sole cropping, and climbing types in intercropping.