The chromosomal aberration test using a Chinese hamster lung cell line (CHL) was carried out on 19 aporphine alkaloids including apomorphine with and without rat liver homogenates (S9) mix. Eighteen of 19 alkaloids tested induced chromosomal aberration in the presence or absence of S9 mix. Among the alkaloids tested, anolobine, liriodenine and 4,5-dioxodehydrocrebanine induced chromosomal aberrations at relatively low concentrations and as low as 2.5, 5 and 3.13 micrograms/ml, respectively. Dicentrine, anolobine and 4,5-dioxodehydrocrebanine induced chromosomal aberrations with high frequencies. Apomorphine induced 10% aberrant cells at 12.5 micrograms/ml in the direct method and 12% at 100 micrograms/ml with S9 mix in the S9 method. Liriodenine which was the most potent mutagen for TA100 with S9 mix and roemerine which was the most potent for TA98 with S9 mix in Ames test were also clastogenic with and without S9 mix.