Aims: To find a clinically practicable parameter for the identification of β-thalassaemia trait (β-TT) in anaemic pregnant women on the basis of routine use of haematological examination. Methods: During 1998–2002, 304 anaemic pregnant women were observed in anaemia consultation hours. A retrospective study was carried out with the aim of finding a screening method for β-TT in anaemic pregnant women. We compared a sensitivity and a specificity of six different parameters for identification of β-TT. On the basis of a sensitivity and a specificity for each parameter, we calculated Youden’s index, the likelihood ratio and determined the receiver-operating curves. The logistic regression of the variables MCV, MCH and microcytosis was accomplished. Results: The analysis using receiver-operating curves as well as a calculation of Youden’s index showed that the best parameter for screening of β-TT in anaemic pregnant women is MCV ≤75 fl. For differentiation between patients with iron deficiency anaemia (IDA) alone and patients with β-TT and concomitant IDA, microcytosis ≥15% was the most sensitive. By using MCH we identified 100% of patients in the group with β-TT but only 67% of patients in the group with IDA. Conclusion: Our results suggest identification of β-thalassaemia on the basis of quantification of HbA2 in all patients with MCV ≤75 fl and normal iron status.