Propofol has been widely used in general anesthesia. Although it is also often used in pediatric anesthesia, there has been only limited scientific evidence on the use of propofol in children up to 3 years. A prospective, randomized, double-blind, therapeutic equivalence study comparing two propofol 1% emulsions (Propofol 1% Fresenius vs. Diprivan 1%) was performed in 60 patients scheduled for routine surgery or for diagnostic laparoscopic procedures requiring anesthesia. To guarantee comparability of age distribution between the two groups, a stratified randomization with patients younger than 12 months of age in a low age group and with patients aged 12 months to 3 years in a high age group was used. The average propofol induction dose and the average propofol infusion dose were analyzed to prove equivalence. The side-effects profile was analyzed to compare the safety profiles of the two propofol formulations in this study. There were no differences in baseline characteristics between the two treatment groups of high and low age. Medications used for induction and maintenance of anesthesia, and side-effects profiles were comparable, as were the average propofol dose for induction of anesthesia (range of the mean dose 4.0-4.2 mg/kg) and for maintenance of anesthesia (range of the mean dose in the first hour 8.74-9.42 mg x kg(-1) x h(-1)). The two 1% propofol formulations were equally effective in our patient population of infants and young children between 1 month and 3 years of age. No differences between the two propofol formulations were found with regard to the circulatory reaction, lipid metabolism, dosages, and recovery profile in the studied age groups.