In a retrospective study, patients who underwent tocolytic therapy by beta-mimetics were investigated. 308 received Fenoterol monotherapy (group A) and 163 a combination of Fenoterol with the calcium-antagonist Verapamil in a dosage-relation of 1/20 (group B). The review of 287 cardiotocograms showed a significant increase in the foetal heart rate in both groups by about 13% after 114 minutes (A) and 146 minutes (B). Although the diaplacental transfer of Fenoterol to the foetus is very small, a high percentage of foetuses showed an increase in heart rate (84.7% in A, 86% in B). There was a significantly longer duration of foetal tachycardia in group B. Both groups were not different in respect of perinatal mortality (5.4% in A, 5.2% in B), birth weight, APGAR score, and the reasons for paediatric care. The great difference in placental permeability for Fenoterol and Verapamil may cause a danger for the foetus. Since no reasonable improvements are seen, additional Verapamil therapy is not recommended.