Our aim was to evaluate the impact of some biochemical, histological and viral factors on both EVR and SVR in patients with genotype 1 chronic hepatitis C (CHC) treated with peginterferon plus ribavirin. Patients and methods: We evaluated retrospectively 188 naïve patients with CHC treated with peginterferon plus ribavirin at standard weight-based doses for 48 weeks. Biopsies were assessed for inflammatory activity and fibrosis. Steatosis was categorized by the proportion of hepatocytes per low-power field with fatty changes: >5%, >5-33%, 34-66%, >66%. Biopsies were also assessed for stainable iron using the Brissot scoring system. All patients were evaluated for metabolic syndrome (MS) using the NCEP-ATP III criteria. Results: EVR was achieved in 115/188 pts (61.17%) while SVR occurred in 82/115 (71.3%). After adjusting for sex and age, independent factors that negatively interfered with both EVR and SVR were: fibrosis score, steatosis, iron score, HOMA-IR index and viral load. After excluding the patients with MS criteria (n=32), EVR was observed in 102/156 (65.4%) and SVR in 82/102 (80.4%). Factors that independently influenced both EVR and SVR were: fibrosis score, steatosis, iron score and viral load. Conclusion: Fibrosis, steatosis and iron scores, as well as viral load are independent parameters that can affect both EVR and SVR in genotype 1 CHC patients, regardless the presence of MS. If MS is present, high HOMA-IR index can also additionally impair viral response.