The aim of the present study was to find out whether the elevation of the serum ceruloplasmin level, previously described in vitamin-A-deficient rats, is a specific phenomenon. Quantitative variations of serum ceruloplasmin, albumin and haptoglobin (whose concentration increased during inflammation) were determined in normal and vitamin-A-deficient rats. Concentrations of ceruloplasmin, haptoglobin, and the value of the haptoglobin to albumin ratio are increased in the serum of vitamin-A-deficient rats compared to normal rats. The results suggested that the increased serum level of ceruloplasmin in vitamin-A-deficient rats was due to the presence of inflammation.