Introduction:Haemorrhagic cystitis (HC) can be chemically induced by cyclophosphamide (CYP) injection; it is mainly used as an immunosuppressive and antineoplastic drug.Tadalafil (TAD) a phosphodiesterase type-5 inhibitor has vasodilator, anti-inflammatory and anti-apoptotic effects.It is mainly used for the treatment of erectile dysfunction and pulmonary arterial hypertension.Aim of the Work: Thi...