Aluminum tolerance screening methods have not been adequately described for sorghum (Sorghum bicolor L. Moench). identification of Al tolerant sorghum is important if this crop is to be grown on many of the acid, Al toxic soils of the world. An Al tolerance screening method using nutrient solutions was developed for sorghum and the optimum conditions described so that good differential responses of genotypes could obtaines. The method allowed for a relatively large number of plants (126) to be grown in the same container of relatively low volume (6.31) and in a small area. Good results were obtained within 10 days from the time plants were treated with Al. The optimum growth conditions were: 148 uM Al, 64 uM P, 7.4 mM ca, 1.6 mM Mg, and day/night temperaturesof 28/23C. High or low levels of mineral elements or temperatures resulted in reduced dry-matter yields, mineral deficiencies, too severe Al toxicity symptoms, or no differential responses among genotypes. Of the parameters measured (Al toxicity symptom rating, root lengths, and top and root dry matter weichts), Al toxicity symptom ratings and root lengths could be used assess Al tolerant of the genotypes, but dry weights could not. Aluminum toxicity symptom ratings appeared to be a more reliable parameter to evaluate Al toxicity than root lengths. Ninety-three sorghum genotypes were screened for Al tolerance. Some of the more Al tolerant genotypes were: NP Yellow 71LN5432, SC110 x SC120 76LN2643, SC116 x SC396, 76LN2474, SC500-6-1, NB4692, Wheatland (...).