This work aims to investigate the antiproliferative properties of Salvia cryptantha on breast cancer. Salvia cryptantha (SC) extracts were studied for cytotoxicity against the breast cancer cell lines. In-vitro apoptosis studies of breast cancer cells were performed by nnexin V staining in flow cytometry analyses Immunohistochemistry studies for Ki-67 and p16 in the tumoral tissue sections of Dimethyl Benzanthracene (DMBA) induced mammary tumor in rats were performed. In-vivo anticancer activity testing was carried out by inhibiting the growth of mammary tumor in rats. SC showed cytotoxicity to three cancer cell lines. Annexin-positive cells level in SC treated cell lines were higher than the untreated control cells. The expression of the Ki-67 decreased in treatment groups compared with the control group. The expression of p16 protein was much higher for the rats treated by SC, compared with the untreated control group. In vivo studies showed that mean tumor volume inhibition ratio in SC treated group was 38 % compared with the untreated rats. These results indicate that Salvia cryptantha has antitumoral potential against breast cancer.