This study was to demonstrate whether loquat leaves protect against 7,12-dimethylbenz[${alpha}$]anthracene (DMBA)-induced breast cancer in female rats. Rats were fed control diet (NC, DC), ethanol (DE), or water extract of loquat leaves (DW) until sacrifice. At 50 days of age, animals in the DC, DE, and DW groups were given a single intra-gastric dose of DMBA (50 mg/kg) dissolved in corn oil. Both the water and ethanol extracts of loquat leaves decreased the incidence of tumors, with water extract having the higher inhibitory effect. Ethanol extract significantly decreased the multiplicity of tumors. Loquat extracts significantly decreased tumor cell proliferation and the tumor grade based on the degree of tubule formation. These results suggest that both water and ethanol extracts of loquat leaves inhibit the development of breast cancer. Such inhibition may be based on the suppression of initiation and tumor cell proliferation.