Embryogenic suspension cultures derived from spear callus led to the development of highly embryogenic calli of Asparagus cooperi. The initial suspension culture was formed in MS basal medium with 2,900 mg l-1 potassium nitrate, 1 mg l-1 α-naphthalene acetic acid (NAA), and 1 mg l-1 kinetin (Kn). A subculturing interval enhanced the formation of embryogenic clumps, and several nitrogenous compounds effectively accelerated the growth rate of such clumps. Embryo development was achieved by transferring embryogenic cell clusters to MS solid medium containing 1 mg l-1 NAA, 1 mg l-1 Kn and 0.2 mg l-1 abscisic acid. The transfer of mature embryos to MS basal medium containing 1 mg l-1 zeatin led to prolific regeneration. All regenerated plants were cytologically stable.