Objectives: Hemolysis is a common problem causing interference on biochemical assays. In this study, we investigated 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 of prealbumin were spiked with different dilutions of the hemolysate, which was prepared according to the classical osmotic 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 were analyzed for three times by the immunoturbidimetric method on AU680 clinical chemistry analyzer. Mean percent changes of prealbumin results were presented with interferographs.,Results: We observed that hemolysis interfered negatively with both normal and low level serum pools. This effect began to exceed the limit of 10% as a critical point in the concentration range 5.31 to 6.25 g/L hemoglobin concentration in both normal and low serum pools. The limit exceeding value was higher in the low serum pool than the normal serum pool (20% and 11%, respectively).,Conclusions: Clinical laboratories must be alert the effect on low prealbumin levels, especially in settings where hemolysis is an increasing problem.