Radiation and Chemotherapy play a major role in the management of patients with malignant tumours, they have marked toxicity against tumour cells in addition to other undesirable side effects on normal organs. This led the researchers to carry out histological, cytological, and histochemical studies as regards the effect of radiation and chemotherapy on the jejunal mucosa of normal mice. Seventy-two male Swiss mice were used in this study. Golgi apparatus, acid phosphatase [ACP], and succinic dehydrogenase [SDH] enzymes were studied in normal jejunum as well as after exposure to radiotherapy and chemotherapy. The results revealed that prominent changes were observed in cisplatin-treated group, while more effects were shown in animals receiving combined radio and chemotherapy.