Background: Recently, we have reported rasam (South Indian spice soup) for antiproliferative activity against Michigan Cancer Foundation-7 cell lines. Objectives: Breast cancer seems to be more common in the younger age group. Considering the deviation of the younger group from the traditional food habits as one of the many reasons of breast cancer incidence, rasam was investigated for its chemopreventive effect on mammary carcinoma. Materials and Methods: Rasam at 3 and 4 mL/kg dose was administered to female Spraque–Dawley rats for 30 days before 7,12-dimethylbenz[a] anthracene (DMBA) induction of mammary carcinoma. Tamoxifen was used as the standard drug. Body weight, thiobarbituric acid reactive substances (TBARSs), phase I enzymes, hexokinase (HK), aldolase (AD), glucose 6-phosphatase (G6P), fructose 1,6-bisphosphatase (F16P), citric acid cycle (CAC) enzymes, histopathology, tumor weight, tumor latency, and tumor incidence were studied. Results: In all the studied parameters such as body weight, TBARS, phase I enzymes, HK, AD, G6P, F16P, and CAC enzymes, rasam-pretreated groups showed better prevention than tamoxifen-treated groups. Histochemical findings also clearly confirm the chemopreventive effect of rasam. Particularly at the dose of 4 mL/kg, rasam was efficient in reducing the percentage of incidence of tumor, number of tumor, and tumor weight. Conclusion: The present study reveals that rasam attenuates the mammary tumor induction magnitude of DMBA in female rats.