Egypt is one of the countries with very high rates of hepatitis C virus (HCV) related morbidity and mortality. However, little is known about geographical and clinical differences in genetic variability of HCV in Egypt. Using direct sequencing and phylogenetic analysis of partial core/E1 and NS5B regions of the HCV genome, HCV genotype/subtype was determined in 129 HCV-infected patients residing in three governates in south Egypt: Assuit, Sohag, and Qena. According to clinical stage of infection, patients were categorized into four groups: asymptomatic carriers, n = 16; chronic hepatitis C patients, n = 36; liver cirrhosis, n = 54; and hepatocellular carcinoma (HCC), n = 23. Genotype 4a was detected in 80.6%, whereas 1g, 4l, 4n, 4o, 4f, and 4m were identified in 7.7%, 4.7%, 3.9%, 1.6%, 0.8%, and 0.8% of cases, respectively. The prevalence of 4a differed regionally; from 88.5% (in Sohag) to 64% (in Assuit, P = 0.002). Genotypes 4l and 4n had a higher prevalence in Assuit (12.8%, 10.3%) than Sohag (0%, 0%; P < or = 0.011). Difference in clinical features of determined genotypes/subtypes was observed; more carriers of non-4a variants (4l and 4n, 4f, or 4m) had chronic hepatitis compared to carriers of 4a (53.3% vs. 23.1%, P = 0.025), while more patients with 4a had liver cirrhosis (45.2% vs. 13.3%, P = 0.023). Two HCV-4o strains were isolated in this study, both from patients with HCC. In conclusion, geographical diversity of HCV was revealed in this study in southern Egypt. A further case-control study is required to confirm the trends of differential pathogenicity of HCV subtypes, indicated by this study.