Purpose Neurogenic bladder is a common complication of several central nervous system injuries. Statins and phosphodiesterase-5 (PDE-5) inhibitors are reportedly beneficial in neural injuries and urinary system dysfunction. The effect of simvastatin, sildenafil and tadalafil on several renal function indices of an animal model of neurogenic bladder was investigated. Methods Forty male rats were assessed in five equal groups. Dura mater and the cord were injured with an aneurysmal clamp at the level of T9-T10 in all rats except in sham group. The sham and control groups (treated by normal saline), simvastatin (4 mg/kg), sildenafil (5 mg/kg), and tadalafil (2 mg/kg) groups received treatment (i.p.) for seven consecutive days following injury. Renal system and motor functions were assessed at day 28 following injury. Data were analyzed by analysis of variance followed by the Student-Newman-Keuls post hoc test. Results Simvastatin improved both the renal and the motor function compared with the control group. However, sildenafil and tadalafil could only improve the motor function but could not make any significant differences in renal indices in comparison with the control group. Conclusion Statins can effectively improve the motor and renal functions in a condition of renal dysfunction in a rat model of neurogenic bladder. PDE-5 inhibitors could help to improve motor function, but are not helpful in renal function, at least in short time.