Large numbers of somatic embryos were obtained from cotton (Gossypium klotzschianum Anderss.) callus cultures by modifying callus source and culture conditions. Reduction of the light intensity received by callus cultures resulted in a 6-fold increase in embryo number. A further 14-fold increase in embryo yield was achieved by the use of somatic embryo-derived callus rather than hypocotyl or mature plant-derived callus for establishment of suspension cultures. The inherent high variability in numbers of somatic embryos obtained per culture was decreased following visual selection of calli for high embryogenic potential. Calli with increased capacity to produce somatic embryos were light green modulated, and slow growing as opposed to calli which were dark green, smooth, and vigorous. Although the embryogenic potential of callus cultures appears to decrease with increasing number of subcultures, we have established a system whereby large amounts of somatic embryos are made available for screening.