Tocolytic drugs are used in order to delay or to abolish preterm labour. These drugs inhibit uterine contractions and have different pharmacological properties. The most used tocolytic agents today are beta 2-adrenergic agonists (isoxuprine, ritodrine). The pharmacological actions, pharmacokinetics, toxicological and clinical aspects of ritodrine, a synthetic beta 2-adrenergic agonist with tocolytic properties are described. Findings of many clinical trials are also discussed.