This study accumulated results of the HCV lookback in Denmark and described the morbidity of the infected recipients. Donor records were identified for at least ten years back, and recipients still alive were tested for hepatitis C. Those with positive results were referred for clinical evaluation. A total of 150 Danish anti-HCV positive donors had donated blood to 1018 recipients of whom 288 (29%) were still alive. Because of age, malignancy or other severe diseases 118 (41%) of these were not contacted. Of 157 recipients screened for HCV, 128 (82%) were anti-HCV positive and 88 (56%) were HCV-RNA positive. Among the HCV-RNA positive recipients symptoms were present in 38% (25/66 reported), elevated ALT was found in 53% (41/77 tested) and cirrhosis was found in 11% (6/54 biopsied). Treatment with interferon-alpha was initiated in 23 patients, corresponding to 26% of HCV-RNA positive recipients.