RESUMO -Este trabalho teve como objetivo avaliar os efeitos do arranjo espacial e da densidade de semeadura na produtividade de cinco híbridos de milho, em dois locais no cultivo de verão. Foram utilizados espaçamentos de 80 cm e de 45 cm entrelinhas, e densidades de semeadura de 42.000, 52.000, 62.000 e 85.000 plantas ha COMBINING ROW SPACING AND POPULATION DENSITY IN INCREASING MAIZE YIELDABSTRACT -This study aimed to evaluate the effects of spatial arrangement and plant density from five corn hybrids at two locations in the summer season. Row spacing used were 80 cm and 45 cm between rows and plant densities were 42,000, 52,000, 62,000 and 85,000 plants ha -1 . The evaluations were conducted in Cascavel, State of Paraná, and RioVerde, State of Goiás, Brazil. Significant effects were observed for the main effects (hybrid, row spacing and density), but there were no interactions between the main effects, with the exception of the interaction between density x hybrid in Rio Verde. There was a greater effect of row spacing than the population density on yield of all hybrids. With the row spacing at 45 cm the hybrids yielded, on average, 36% more than at a spacing of 80 cm, in the two locations. There was a trend for increased productivity with increased seeding rate up to 75,000 plants ha -1 in Cascavel, and up to 85,000 plants ha -1 in Rio Verde.