The pharmacokinetics and relative bioavailability of fluoxetine capsules manufactured by two different pharmaceutical factories were carried out. A multiple oral doses ((20 mg/cap) × 2/day × 13 day)of fluoxetine was administered in 8 healthy young Chinese males in a completely double-blind cross-over design with a two week washout period between each dose. Plasma samples were obtained before (three minimum concentrations) and at various appropriate intervals after last dosing up to 72 hours. The plasma concentrations were then analyzed by a HPLC method. The limit of quantitation of this HPLC method was 5 ng/mL. The coefficients of variation of the within-day and between-day calibration curves (n = 6) range from 5 ng/mL to 500 ng/mL were less than 16 %, and the accuracy of this method was also verified. Values for the area under the plasma concentration-time curve at steady state (AUC), peak concentration (Cmax), time to peak concentration (Tmax), elimination rate constant, half-life, oral clearance were estimated and compared for each preparation. By ANOVA, power analysis, 90% confidence interval, and two one-sided tests, PROZAC and FLUOXETINE can be considered bioequivalent.