Seven maize cultivars and seven soyabean cultivars were grown in monocultures, and in all possible 49 mixtures of maize and soyabean, at two locations to assess the intercropping advantages of mixtures. On average, intercrops produced 6% more dry matter and 17.5% more protein than the monocultures of maize, the most productive component. Both the dry matter and protein yields of intercrops were closely correlated with the yield of the maize component, but not with that of the soyabean component, indicating that there was no need for a specific breeding programme for maize to be used in intercropping systems. Although the average intercropping advantage, the monoculture yields of maize cultivars and, to a lesser extent, the monoculture yields of soyabean cultivars differed between locations, there was no evidence that the yield of various intercrop combinations differed between locations.