Various prognostic factors for survival have been identified in patients with colorectal cancer. However, although it has been suggested that the pre-treatment serum albumin concentration is a prognostic indicator in certain malignant diseases (melanoma, prostate cancer, leukaemia), its value in patients with colorectal cancer remains unclear. This study investigated the prognostic value of serum albumin in this patient group. A total of 431 patients presenting to the Professorial Surgical Unit between 1972 and 1985 were analysed in this study. Using the Cox proportional hazard model, age, tumour stage (Dukes' stage) and tumour differentiation were shown to be independent prognostic factors for survival in patients with localized colorectal cancer. In addition, the pre-treatment serum albumin concentration was found to be an independent prognostic indicator. This is the first such documentation for patients with 'curable' colorectal cancer.