Aim: To evaluate the safety and efficacy of Vitamin D supplementation in erectile dysfunction patients with Vitamin D deficiency. Material and Method: This study was carried out in Department of Urology, S.M.S. Medical College and attached Hospitals between March 2018 to April 2019 among patients in the age group 20-60 years presenting with ED and having severe Vitamin D deficiency. Patients were randomized into three groups. First group was treated with Tadalafil 10mg once a day while the second group had Tadalafil 10mg once a day plus Vitamin D 60,000 IU once a week, and third group was given Vitamin D 60,000 IU once a week only. Efficacy of drugs was evaluated at base line and after 12 weeks on the basis of International Index of Erectile Function Questionnaire scoring. Results: After 12 weeks of treatment IIEF-5 scoring was nearly same as that of the base line with no significant difference in group C patients. On the other hand, IIEF-5 scoring was significantly improved in group A and B patients (P<0.001). On comparing group A and B patients there was significant improvement in group B compared to group A (P < 0.05). In comparison to group C, group A and group B patients had more side effects (P<0.05), but of mild intensity and prescribed medications were well tolerated. Group A and B patients had no significant difference in side effects. Conclusion: This study showed that the use of Tadalafil in combination with Vitamin D in Vit D deficient ED patients act better than Tadalafil or Vit. D alone.