Background: The recurrence of nephrolithiasis has high incidence in northern region of India posing major health problems. Aim and Objectives: To study the efficacy of Unani pharmacopeial formulation Safoof Hajrul Yahood (SHY) in preventing recurrence of nephrolithiasis. Study Design: Open labeled, single arm, clinical trial. Materials and Methods: The study was conducted on 75 cases of uncomplicated nephrolithiasis (Hisat al Kuliya). The post-trial assessment was done on 49 cases after five years. Subsequent to written and informed consent, patients of All genders between 18-60 years with 6-8mm calculi were given SHY (5g twice daily orally for 8 weeks). Patients were followed up fortnightly, investigated at day 0, 15 and 60 and enquired about their diet and fluid intake. The data was analyzed on Tukey-Kramer multiple comparison test and paired t test. Results: Mean age of patients was 33.45±10.99 years CI (30.92-35.99). SHY reduced 24 hr calcium excretion highly significantly (p<0.0001). Calculus clearance rate was 64% and recurrence after five years was 29.16%. The drug was well tolerated. Conclusion: SHY probably corrects crystalloid colloidal imbalance or the oxalate metabolism and/or renal functions; thus, preventing recurrence. However, the exact mechanism of the drug needs to be studied.