Abstract: This study was designed to evaluate the anti-mutagenic potential of Myristica fragans (Nutmeg) in male rats. Twenty male wistar rats were randomly distributed into four groups. The treatment groups were administered doses corresponding to 0, 200, 400 and 600 mg kg-1 b.wt. of nutmeg aqueous extract for a period of eight weeks. Data were collected on bone marrow micronucleus index, sperm head abnormality and mutation index. Analysis of variance revealed significant (p<0.05) reductions in sperm head abnormality in the nutmeg treated animals, as compared with the control, in a dose dependent manner. The control had the highest value for sperm head abnormality (6.18±0.55), while 600 mg kg-1 b.wt. group had the lowest value (3.80±0.09). Micronucleus index values in the 600 mg kg-1 b.wt. group (1.40±0.25) was significantly reduced, as compared with the control (3.60±0.51). It was also observed that the mutation indices decreased in a dose dependent manner, from 0.00 in the 0 mg kg-1 b.wt. group to -0.384 in the 600 mg kg-1 b.wt. group. Nutmeg extract showed anti-mutagenic properties, which means the plant contains phyto-antimutagens that could be exploited further in drug development, or as standardized phyto-preparations.