Aegle marmelos is widely used in Indian Ayurvedic medicine for the treatment of diabetes mellitus. In thepresent study, cancer chemopreventive properties were evaluated on 7, 12-dimethylbenz (a) anthracene (DMBA)induced skin papillomagenesis in Swiss albino mice. A single topical application of DMBA, followed 2 weekslater by repeated application of croton oil till the end of the experiment ( i.e. 16 weeks) caused a 100% tumorincidence. In contrast, mice treated with the AME (50 mg/kg b. wt./animal/day) in the peri-initiational phase(i.e. 7 days before & 7 days after DMBA application; Group IV) and post-initiational phase (from the day ofcroton oil treatment till the end of the experiment; Group V), exhibited a significant reduction to 70 and 50%respectively. The cumulative number of papillomas after 16 weeks was 67 in the control group, but 26 and 23 inthe animals treated with AME at peri-initiational and post-initiational stages, respectively. The tumor burdenand tumor yield were significantly decreased (Group IV-3.7, 2.6; Group V- 4.6, 2.3) as compared to carcinogentreated control group (6.7, 6.7). The present study demonstrates the chemopreventive potential of Aegle marmelosfruit extract on DMBA induced skin tumorigenesis in mice.