Japanese quail (Coturnix coturnix jap?nica) raised on commercial mashes selected stable diets from combinations of 12 different kinds of seeds. Attainment of a stable preference required a short period (3-5 days),, although the birds had never before seen whole seeds. Birds generally maintained their weight and health when presented a variety of seeds, but single-seed diets were accompanied by losses in weight and sometimes death. In some instances there were significant differences in the seeds selected by males and females. Among the nutritional and physical factors tested, seed shape, color and fiber content were most often correlated with seed preference. Preliminary tests also indicate the possible importance of early exposure upon later seed selection patterns.