<p>In humid tropical zones of Mexico maize (<em>Zea mays</em> L.) is an important crop in human and animal feed. Six maize genotypes were studied to evaluate grain and leaf production, under three plant densities (50,000; 62,500 and 83,333 plants ha^-1). The assay was carried out at the Papaloapan University Campus Loma Bonita, Oaxaca. Genotypes used were: DK-357, HE-1A17, H-520, NH5, H-564C and the synthetic variety VS-536. Experimental design consisted of a randomized blocks. Each experimental plot was 12.8 m². Variables studied were: plant height (cm), days to male flowering, days to silking, ear weight (g), ear length (cm), number of grains per ear, weight of a hundred grains (g), grain yield (kg ha^-1), and dry leaf yield (kg ha^-1). An analysis of variance was performed for genotypes, densities, and genotypes by densities interaction. In addition, a Tukey test for pairwise comparison was run (P<em> </em>≤ 0.05). There were significant differences among genotypes, densities and genotype by density interactions. The hybrid H-520 produced the highest grain yield (5,993.3 kg ha^-1). The synthetic variety VS-536 showed higher leaf yield than anyone else.</p>