Objectives: Hemolysis is a common problem causinginterference on biochemical assays. In this study, weinvestigated the effect of in vitro hemolysis on the measurement of prealbumin, using normal and low prealbumin concentrations.Methods: Serum pools containing normal and low levels ofprealbumin were spiked with different dilutions of thehemolysate, which was prepared according to the classicalosmotic shock procedure. The final concentrations of hemoglobin in the samples were 10.63, 6.25, 5.31, 2.66, 1.33, 0.66,0.33 and 0 g/L. The prealbumin levels in these samples wereanalyzed for three times by the immunoturbidimetric methodon AU680 clinical chemistry analyzer. Mean percent changesof prealbumin results were presented with interferographs.Results: We observed that hemolysis interfered negatively with both normal and low level serum pools. Thiseffect began to exceed the limit of 10% as a criticalpoint in the concentration range 5.31 to 6.25 g/L hemoglobin concentration in both normal and low serumpools. The limit exceeding value was higher in the lowserum pool than the normal serum pool (20% and 11%,respectively).Conclusions: Clinical laboratories must be alert the effecton low prealbumin levels, especially in settings wherehemolysis is an increasing problem.