Abstract. The present study aims at the phytochemical profiling of lyophilized pure fruit juice powder of Citrus limon and demonstrates its efficacy as an antitumor agent against human breast cancer cell line (MCF-7). The cytotoxicity was evaluated using the changes in cell morphology, cell viability, and DNA fragmentation, the percentage of cell viability was determined by MTT assay. Our results showed that lyophilized pure fruit juice powder of Citrus limon inhibited the proliferation of human breast cancer cell line MCF-7 with an IC50 98.16 μg/ml at 48 h incubation, it was shown to promote apoptosis as seen as DNA fragmentation using ladder assay. These results suggest that lyophilized pure fruit juice powder of Citrus limon has antiproliferative effect against MCF-7 cell by suppressing its growth.