The estimated prevalence of hepatitis C virus (HCV) infection in the US is 1.8 %. Data are limited on the clinical profile of the disease at first presentation and dynamic follow-up of ALT level, especially in publicly-funded patients. This information is critical for optimal management of these patients. The present study is aimed to assess the clinical profiles of chronic hepatitis C (CHC) at first presentation and clinical implication of dynamic follow-up of ALT level in a county medical center setting. A total of 294 patients were selected from the population consecutively evaluated in the Hepatitis Clinic at Los Angeles County-USC Medical Center between Jan. 1990 and Dec. 1998. Ethnicity of the patients was Hispanics-49.0%, Caucasian-28.6%, African American-13.6%, and Asian-8.8%. Risk factors were identifiable in 84.0% of patients, and injection drug use (IDU) represented the leading risk factor for HCV acquisition (47.4%). History of alcoholism was present in 39.1%. The initial clinical diagnoses were chronic hepatitis 76.9%; compensated cirrhosis 20.4%; and decompensated cirrhosis 2.7%. Elevation of ALT, alpha fetoprotein (AFP), ferritin, and anti-nuclear antibody (ANA) titer were seen in 219/294 (74.5%), 60/194 (30.9%), 20/83 (24.1%), and 35/97 (36.1%) patients, respectively. Anti-HBc (total) test was positive in 65/129 (50.5%) patients. The presence of cirrhosis was significantly associated with age greater than 55 years at entry, female gender, non-African American ethnicity, history of transfusion, lower level of albumin and elevated level of AFP. Longitudinal observation of ALT changes in 178 patients who had neither evidence of cirrhosis at entry nor received interferon treatment showed persistently normal, intermittently or persistently elevated ALT level in 15.2%, 38.3%, and 46.6% patients, respectively. The frequency of developing clinical evidence of cirrhosis during follow-up was significantly higher in patients with persistently (16.0%) or intermittently (7.0%) elevated ALT than that in patients with persistently normal ALT (4.0%). In conclusion, the present study analyzed the clinical profiles of CHC, assessed risk factors for developing cirrhosis, and demonstrated the clinical value of dynamic follow-up of ALT level in a cohort of publicly-funded patients. These data have major implications in designing optimal strategies for disease management, antiviral therapy, and screening for hepatocellular carcinoma in patients with CHC.