The crude saponins from the shoots (edible part of asparagus) of asparagus (asparagus crude saponins; ACS) were found to have antitumor activity. The ACS inhibited the growth of human leukemia HL-60 cells in culture and macromolecular synthesis in a dose and time dependent manner. The ACS at 75-100 micrograms/ml range was cytostatic. ACS concentrations greater than 200 micrograms/ml were cytocidal to HL-60 cells. The ACS at 6 and 50 micrograms/ml inhibited the synthesis of DNA, RNA and protein in HL-60 cells by 41, 5, and 4, respectively, or by 84, 68 and 59%, respectively. The inhibitory effect of ACS on DNA synthesis was irreversible.