Background and objectives: Cyclophosphamide is an effective anti-cancer drug widely used 
in the treatment of many types of cancers, e.g., acute and chronic leukemia, lymphomas,
breast cancer, ovarian cancer, neuroblastoma, and sarcoma. It is also used in 
immunosuppression disorders. Several health hazards were reported after cyclophosphamide 
administration in animal and human models. Many adverse effects are related to 
cyclophosphamide and include chemotherapy-induced nausea and vomiting, bone marrow 
suppression, stomach ache, hemorrhagic cystitis, diarrhea, darkening of the skin and alopecia 
(hair loss). Materials and methods: Twenty- four adult male albino rats were divided into 2 
groups (n=12 per group). The control group (C-group), received only standard diet and
water. The cyclophosphamide 2 weeks group (CP-2W), received intraperitoneal injection 
of a single sublethal dose of 300 mg /kg body weight and rats were sacrificed after 2 weeks.
Results: There were marked structural changes in intestinal mucosa of CP-2D group in the 
form of Inflammation, degenerative changes and apoptosis. Conclusion: Single intraperitoneal injection of cyclophosphamide causes massive distruction in the intestinal mucosa.