The aim of the study was to examine whether Momordica fruit extract (MFE) and Momordica leaves extract (MLE) might exert any chemopreventive effect in a two stage protocol in skin carcinogenesis with Swiss albino mice. The tumour incidence, tumour yield, tumour burden and cumulative no. of papillomas were found to be higher in the controls (without either extract) as compared to the MFE or MLE treated experimental groups. In a melanoma model, the mice which received fruit and leaf extracts of Momordica at the doses of 500 and 1000 mg/kg body weight for 30 days showed increase in life span of animals and tumour volume was significantly reduced as compared to control values. In cytogenetic studies, a single application of Momordica extracts at doses of 500, 1000 and 1500 mg/kg body weight, 24 hours prior the i.p. administration of cyclophosphamide, significantly prevented micronucleus formation and chromosomal aberrations in a dose dependent manner in bone marrow cells of mice. The present study demonstrate chemopreventive potential of Momordica fruit and leaf extracts on DMBA induced skin tumorigenesis, melanoma tumour and cytogenicity.