Grain maize in south-east England showed a markedly flat-topped curvilinear response between density and grain yield, maximum yields being obtained over a range of 80,000–120,000 plants/ha, but yields were reduced at less than 70,000 plants/ha. A general density recommendation of 80,000–90,000 plants/ha is suggested, or a seed rate of 95,000 seeds/ha to allow for germination losses. Yields of cv Anjou 210 and DeKalb 202 showed some decline when the density exceeded 100,000 plants/ha, whereas yields of Pioneer 131 increased above this value and 100,000 plants/ha can hence be recommended. Although planting above the optimum density markedly increased the incidence of stem lodging at harvest, only a minor delay in stage of maturity occurred.