In 420 pregnant women who delivered during the third trimester at the "Istituto di I Clinica Ostetrica e Ginecologica", University of Catania, routine blood tests were performed in 95.5% of cases (401 women), urine tests in 95.5% (401), Hb-phoresis in 42.6% (179), HBsAg in 51.4% (216), TORCH and urine cultures in 37.8% (159), cardiotocograph in 73.1% (307), plasma RIA of E3 and/or HPL in 35% (147), maternal ECG and pseudocholinesterasemia in 83.6% (351) and 37.6% (158) respectively. No routine diagnostic tests were performed in 4.5% (19 women) of cases. Diagnostic tests are less frequently performed in women, plurigravida, and in pregnancies which follow a physiological course. Several diagnostic tests, except for TCTG and HBsAg, are performed more frequently in pregnancies with complications. Lastly, there is a marked difference between the number of diagnostic tests performed and the individual woman's place of residence.