Comparison of the results for α 2-antiplasmin activity of plasma samples (n = 61, range 0–125%) obtained by the “immediate plasmin inhibition test” (IPIT) and by the automated method for the MLA Electra 1000C of Dade R shows a good correlation (R = 0.935) but a systematic disagreement especially relevant in the range below 40%. An improved method for the detection of α 2-antiplasmin activity on the automated coagulation analyzer MLA Electra 1000C was developed. A linear calibration curve up to 150% was observed. A dilution curve of normal pooled plasma with plasma of an α 2-antiplasmin deficient patient shows a linear curve (y = x+7).