The effect of temperature on the germination of four genotypes of peanuts (Arachis hypogaea L.) was evaluated. Genotypes were identified as L3, L6, L18 and L20. Trials for each genotype were carried out using a completely randomized design with four replications of 50 seeds each. Germination temperatures considered in each trial were 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, and 38 degrees C. The variables evaluated were germination percentage and germination speed index. Minimum, optimum and maximum germination temperatures were also determined. In general, the results obtained for the four genotypes under study in both germination percentage and speed index were significantly higher at temperatures between 30 to 32 degrees C compared to those obtained at temperatures of 12 degrees C and 38 degrees C. The optimum germination temperature (T-o) for the genotypes evaluated ranged between 30.5 and 33.4 degrees C. Minimum germination temperature (T-b) varied from 11.3 to 12.5 degrees C, while maximum temperature (T-m) ranged from 40.8 to 44.9 degrees C.