Objective: The aim of the study was to determine the effects of zinc and melatonin supplements on the immunity parameters of female rats with breast cancer induced by DMBA. Methods: Group 1; Control, Group 2; 7,12-dimethylbenz[a]anthracene (DMBA), Group 3; DMBA + zinc, Group 4; DMBA + melatonin, Group 5; DMBA + zinc + melatonin. The rats’ breast cancer was induced by DMBA 80 mg/kg. Groups 3–5 received daily 5 mg/kg doses of zinc, melatonin, and zinc + melatonin, respectively. Lymphocyte rates, T-lymphocyte subgroups, B-lymphocyte and natural killer cells (NK), and natural killer T (NKT) were evaluated. Results: The most significant increase in lymphocyte, T-lymphocyte, and CD4 lymphocyte rates was found in Group 5. The highest NKT cell rates were found in Group 3. Conclusions: Findings show that zinc and melatonin supplements have led to an increase in the immunity parameters of rats with breast cancer.