A series of experiments investigated early pleiotropic effects of a gene for imperfect albinism (s(al-c) in a population of chickens at Jouy-en-Josas, France. An elevated incidence of lesions of the navel, hocks, and nares typical of imperfect albinos were seen on these chicks, confirming their existence in this population. Variations in hatching environment and the amount of light in the hatcher both implicated in contributing to the occurrence of lesions of the hocks and nares, but not to those of the naval. In two experiments, using batteries and cages, early growth was reduced among albinos and early mortality was increased. Significant genotype by environment interactions for weight at 4 days and growth to this time, but not thereafter, suggested that the effect is restricted to this time. Unfavorable environments were most deleterious to albinos. In a third experiment, conducted in floor pens, the gene had no effect on either early growth or mortality. There was no effect of the gene on the lesions, early growth, or mortality when carried by heterozygous males (s+/s(al-c)).