Background: Use of biomarkers particularly under in vivo condition is of importance in risk assessment. This study is proposed to identify the in vivo antigenotoxic potential using dominant lethal mutation test in B(a)P exposed, turmeric fed animals and evaluate the role of turmeric in counteracting the germ cell mutations. Methods: Twenty four male mice were taken and divided into 4 groups each group containing 6 mice/group. The first and second group received stock diet (control) while the third and fourth groups received 5% turmeric diet for a period of one month. At the end of feeding period, second and fourth group received a single dose of benzo(a)pyrene 1mg/mouse intraperitoneally. After 1 week each male mouse was mated to 3 female mice at 1,4, 8 and 12 week intervals. On 13th day from mid point of mating, the females were sacrificed and live and dead embryos were counted to study the pre and post implantation loss of embryos. The differences in the frequencies of pre and post implant deaths were done by comparing treated with control group at 4-time periods by analysis of variance (ANOVA) and chi-square test which is used to compare treatment group and positive control with negative control. Results: Feeding of 5% turmeric and treatment with a single dose of B(a)P did not show any significant effect on the mutagenic index or the frequency of pregnancy in treated groups compared with control. There was no apparent induction of dominant lethal mutations in B(a)P or B(a)P+Turmeric treated groups. No post implantation dominant lethal effects produced by B(a)P could be detected in this study. The induction of B(a)P and treatment with turmeric did not influence the dominant lethal test. Conclusion: B(a)P did not produce a significant increase in the dominant lethal mutations. Turmeric also did not give any positive response and may be considered as non-mutagenic. The negative result suggests that under the conditions of the test the test substance may not be genotoxic in the germ cell of the treated sex of the test species.