Combination treatment with pegylated interferon (Peg-IFN) and ribavirin remains the gold standard in the treatment of chronic hepatitis C. This therapy is limited by many side-effects including anaemia, neutropenia and reduced quality of life. The use of adjuvant agents to reduce the frequency of dose reductions because of haematological side-effects has been proven to be effective but there are few reports of what effect the use of these adjuvant therapies is having on sustained virological response (SVR). The aim of the study was to assess the clinical impact on sustained virological response of adjuvant therapies during combination therapy with Peg-IFN and ribavirin for chronic hepatitis C. A total of 132 patients, 96 males, were included in the study. The overall SVR was 66.7%, with 50% of genotype 1/4/6 (n = 27/54) patients achieving SVR and 78.2% of genotypes 2/3. The overall SVR of the treatment naïve patients (83/121) was 68.6%. Fifty-one of these patients were genotype 1 with 49.0% (25/51) of this group achieving SVR. The genotype 2/3 group of treatment naïve patients reached an SVR of 82.9% (58/70). Adjuvant therapy was used in 57 patients (43.8%). With the use of supportive adjuvant therapy, we achieved an overall SVR of 66.7% and in treatment naïve patients 68.6%. In genotype 1 patients, SVR rates of up to 46% have been reported in previous studies without the use of erythropoietin and granulocyte colony stimulating factor. We have demonstrated the SVR for genotype 1 can be improved to 50% overall.