Objective: Double-J stent is a common tool used in urological procedures that is inserted for 2–6 weeks, but it may induce abdominal and flank pain, incontinence and irritative urinary symptoms. Alleviation of such symptoms would be useful to improve the patients’ quality of life. Accordingly, in this study, the efficacy of cystone versus tamsulosin in the treatment of double-J stent-related lower urinary tract symptoms was determined. Materials and methods: In this randomised clinical trial, 128 patients who required double-J stent insertion after transureteral lithotripsy during 2018–2019 were enrolled. They were randomly assigned to receive either cystone, tamsulosin, both, or placebo. The international prostate symptom score and visual analogue score data were recorded at baseline, after 2 and 4 weeks across the groups. Results: The international prostate symptom score and visual analogue score factors were statistically different across the case groups receiving cystone, tamsulosin and both drugs versus placebo ( P=0.001). Two weeks after drug administration, the visual analogue score and international prostate symptom score were not statistically different in the tamsulosin, cystone and dual therapy groups; however, after 4 weeks the cystone group had the lowest symptoms. Conclusion: Both tamsulosin and cystone are efficient drugs which would relieve stent-related lower urinary tract symptoms. The administration of cystone with or without tamsulosin for 4 weeks may have the best result in reducing the visual analogue score and international prostate symptom score. Level of evidence: Level I, 1b, therapeutic study, randomised controlled trial