Recent scientific evidence recommends that many of the adverse effects of chemotherapy can be prevented by remedying treatment with antioxidants, minerals, carbohydrates, proteins, and organic acids. The current research was performed to assess haematopoietic and immunomodulatory effects using sap of traditional tree, Borassus flabellifer, in cyclophosphamide induced haematotoxicity and immunosuppression in wistar rats. For eleven consecutive days, the animals were orally pre-treated with Borassus flabellifer sap (3.6 mL/kg). These animals were intra-peritoneally injected on the sixth day with cyclophosphamide (150 mg/kg) and sacrificed five days later. On the final day of the trial, blood samples were obtained from each rat and carried out evaluation of haematological (red blood cells, haemoglobin, mean corpuscular haemoglobin concentration, reticulocytes & serum iron content) and immunomodulatory (total leucocyte count, cellular immune response & tumor necrosis factor-α) parameters. To determine their index values, each rat's thymus and spleen were separated. By elevating red blood cells, haemoglobin, mean corpuscular haemoglobin concentration, reticulocytes & serum iron content, sap of Borassus flabellifer demonstrated an important protective role in cyclophosphamide mediated haematotoxicity. It has also shown substantial resistance against immunosuppression caused by cyclophosphamide by increasing the immunity boosting white blood cells and decreasing the hypersensitivity reaction and tumor necrosis factor-α level at the 3.6 mL/kg dose. The current research shows that therapy with traditional Borassus flabellifer sap has a major protective effect against oxidative stress, haematotoxicity and immunosuppression against cyclophosphamide induced haematotoxicity and immunosuppression.