We describe a 62-year-old woman with advanced chronic hepatitis C who showed no response to low-dose long-term interferon-beta monotherapy (3 MU, three times a week). The interferon monotherapy was continued for 2 years and 9 months. Despite this lack of response to interferon, the patient's clinical course was good and liver function assessed by (99m)Tc-galactosyl human serum albumin single photon emission computed tomography ((99m)Tc-GSA SPECT) analysis improved significantly. Improvement of the data obtained by (99m)Tc-GSA SPECT analysis justified continuation of the treatment. (99m)Tc-GSA SPECT analysis was clinically useful to evaluate the effect of interferon in a patient with interferon non-responsive chronic hepatitis C, despite a lack of reduction of the ALT level and HCV-RNA titer.