HCV infection is the main cause of chronic liver diseases. The current standard treatment for chronic HCV is not satisfactory especially with the moderate response rates and currently known side effects for the treatment. Many coming reports showed the possible role of vitamin D supplementation in augmenting the response to SOC therapy of HCV. Aim of work: Comparison of (SVR) between standard of care group and standard of care plus Vit. D group and to determine the incidence of Vit D deficiency in chronic HCV patients and its possible relation to the degree of hepatic fibrosis. Methods: 101 chronic HCV patients classified into two groups: (Group 1): received the SOC therapy consisted of Peg-Interferon/Ribavirin (51 patients), (Group 2): received the SOC therapy consisted of Peg-Interferon/Ribavirin+ Vitamin D3 (50 patients). Results: vitamin D deficiency was found in 100 % of group 1 and in 90% of group 2 .After Vitamin D supplementation and optimization of the serum levels, no positive impact was observed on treatment outcome where SVR was achieved in 51.2 % in cases group and 71.4 % in control group by per-protocol analysis and in 44% in cases group and in 68.6 % in control group by intention to treat analysis with no statistically significant difference, also no correlation was found between 25(OH) D levels and fibrosis score at baseline assessment of the whole 101 studied populations. Conclusion: Though the optimistic data previously documented about the results of vitamin D supplementaion on HCV treatment ,in the current study no significant impact on SVR rates and no solid correlation was found between vitamin D levels and degree of liver fibrosis.