Ciprofloxacin (CAS 85721-33-1) is a gyrase inhibitor used against a wide number of bacteria which develops a very low bacterial resistance. Its pharmacokinetics has been extensively studied using two main methods, liquid chromatography and microbiological assay. The pharmacokinetics of ciprofloxacin administered orally was evaluated in healthy Mexican volunteers after a dose of 500 mg. Ciprofloxacin was assayed from plasma by a specific HPLC method reading absorbance at 280 nm. Pharmacokinetic parameters were similar to reported values, including a previous study on Mexican healthy volunteers with the microbiological assay. AUC was 12.11 mg h/l, Cmax 2.44 mg/l, tmax 0.79 h and half-life 3.8 h. tmax was slightly shorter than those in other studies. Ciprofloxacin presented no adverse reactions and can be dosed to people with Amerindian origin in the same dose regimes as prescribed to Caucasians in order to achieve minimal inhibitory concentrations against a wide range of microbial pathogens.