The object of this study was to determine whether the pharmacokinetics of levodropropizine were linear. Twelve healthy adult male volunteers received oral doses use of 30, 60 and 90 mg of levodropropizine. A cross-over design was used. With the exception of Cmax, and AUC the pharmacokinetics of levodropropizine in the dose range studied are similar. The relationship between the doses and AUCs and the statistical comparison of AUCs (Anova test and Westlake test) confirm that in the range 30-90 mg the plasma pharmacokinetics of levodropropizine are linear.