The main objective of this work was to quantify the lipophilicity of sarafloxacin in the form of the apparent and true partition coefficient in an n-octanol/buffer system. For that purpose the ionization constants were determined by a spectrophotometric method, and the distribution profiles of microspecies in water as a function of pH for this fluoroquinolone were established. The maximum concentration of the neutral species occurs at the sarafloxacin isoelectric point, pH = 5.5. The apparent partition coefficient in the n-octanol/buffer system versus the pH profile of sarafloxacin displayed a parabolic behavior that reached a maximum near the pH of the isoelectric point. The true partition coefficient was calculated from the log P(app) and microconstant values and has the value of 0.846 +/- 0.021.