To assess the bioequivalence of two levofloxacin 500 mg tablets marketed in Mexico. The clinical investigation was designed as a randomized, open-labeled, two-part, two-treatment, two-period crossover study, in 27 healthy male volunteers. 1 tablet of each formulation was administered with 200 ml of water after 10 h overnight fast. After dosing, serial blood samples were collected for a period of 24 h. Plasma concentrations were determined by a validated high-performance liquid chromatographic method and pharmacokinetic parameters were obtained by non-compartmental approach. Analysis of variance (ANOVA) was carried out using log-transformed AUClast, AUC yen and Cmax and untransformed tmax, and 90% confidence intervals for AUClast, AUC yen and Cmax were calculated. If the 90% confidence intervals (CI) for AUClast, AUC yen and Cmax fell fully within the interval 80 - 125%, the bioequivalence of the two formulations was established. The means (test and reference) for AUClast were 58.869 and 56.297 microg x h/ml, for AUC yen were 63.456 and 60.748 microg x h/ml and for Cmax were 8.691 and 8.445 microg/ml. The geometric mean ratios of the test formulation to reference formulation for AUClast, AUC yen and Cmax (CI) were 104.53% (102.73 - 106.36%), 104.37% (102.04 - 106.75%) and 103.45% (95.57 - 111.97%), respectively. All 90% CI for AUClast, AUC yen and Cmax fell within the Mexican Federal Commission for Prevention of Sanitary Risks (COFEPRIS) accepted bioequivalence range of 80 - 125%. Based on the results, the formulations tested are bioequivalent.