Delayed emergence, increased incidence of seedling disease, and poor stands are documented effects of poor cottonseed quality. We evaluated the effects of reduced seed quality by two seed deterioration techniques on subsequent plant height and yield in uniform stand densities. Seed were deteriorated using the accelerated aging and hot water methods then seeding rates were adjusted to compensate for expected differences in seed quality. Seedlings were randomly thinned to uniform distributions in April and May planted tests conducted in 1986 and 1987. A slight decrease in plant height and a trend of reduced lint yield was associated with deteriorated seed. The relative effects of seed deterioration were increased in tests having more harsh environments in the seed and seedling stages. By reducing interplant competition by randomly thinning to uniform stands, the adverse effects of seed deterioration-were low.