Abstract: Ninety-two positive samples for anti-HCV antibodies were selected from out patients of Center of Cardiac and Digestive System, Sohag, Egypt aged from 20 to 55 years. Then, confirmed by Reverse Transcription Polymerase Chain Reaction (RT-PCR) for HCV. The confirmed patients were received 12 vials of BEG IFN-2a for 12 weeks (180 IU mL-1 weekly) plus ribavirin (1000 mg for ≤75 kg or 1200 mg for >75 kg-Roche) and follow up by RT-PCR. The results showed that 67 patients (72.8%) responded to the treatment (group A) while 25 patients (27.2%) non responders (group B). The two groups were Screened for Serum Alanine Transaminase (ALT), Serum Aspartate Transaminase (AST), Serum Alpha Fetoprotein (AFP), serum albumin, serum creatinine, Serum TSH, Hemoglobin (Hb), White Blood Cells Count (WBCs) and Platelets count. Hematological disorders and ALT elevation were common side effects of treatment. The side effects were increased within group B than that of group A. Three random Hepatitis C Virus (HCV) samples from group B were studied for the diversity and sequence variations. Sequencing of 223 nucleotide of 5'-untranslated region (5'-UTR) was performed. In the phylogenetic analysis, the three sequences and 80 sequences of HCV different genotypes from GenBank were used. Nucleotide variations were found in 7 (3.14%) of the 223 nucleotide positions analyzed. The variations were observed in the nucleotides (74, 92, 112, 113, 133, 172 and 180). Nucleotide insertion was seen in one sequence in the nucleotide position of 212. Root Neighbor-joining (NJ) tree revealed that the three HCV samples could be classified as genotype 4. Two of the three samples were closely related (98.2%) while the third clustered with isolate from Gabon (98.7%). The third isolate may be a new subtype but this will require an in-depth exploration on sequence variability in at least two coding regions.