1- Objectives: Ureteral stenting is a common intervention in endo-urological procedures. Despite the usefulness of stents, however, patients experience various stent-related symptoms. Lower urinary tract symptoms have significant impacts on patients’ health related quality of life. There are several medical modalities for symptom relief, and Tadalafil is one of the recent therapeutic options. This study is designed to evaluate the effects of Tadalafil on alleviation of lower urinary tract symptoms, pain, general health, sexual life and also work status of patients with ureteral stents based on Ureteral Stents Symptom Questionnaire. 2- Design: In this Randomized Controlled Trail, patients were randomly allocated to the intervention (Tadalafil) or Placebo groups after a computer based random block designation and receive encoded drug packages by head nurse of surgery room, who is unaware of the research process. None of the physicians, nurses, patients, outcome assessor and statistical analyzers is aware of designated intervention. 3- Setting and Conduct: Patients receive treatment with Tadalafil or placebo for 4 weeks after ureteral stent insertion and first follow up session was programmed to be 4 weeks after intervention. 4– Participants: Inclusion criteria: Male patients (+15 years) who underwent unilateral ureteral stenting. Exclusion criteria : Hypertension; history of heart disease; respiratory disease; stroke; hypotension; renal or liver failure; retinitis pigmentosa; severe headache; consumption of nitrate drugs and a positive urine culture, or who had any allergic reaction to Tadalafil 5- Interventions: Patients receive interventions randomly (Tadalafil or placebo) for 4 weeks with a daily pill. 6- The main outcome variables: The rate of stent related lower urinary tract symptoms (lower urinary tract symptoms, pain, general health, sex and working status) and secondary outcomes are the possible side effects.