Six polymorphic modifications of Balofloxacin (Q-35) were obtained by the recrystallization from different organic solvents and characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD). The dissolution patterns of these six modifications were also checked in distilled water at $37{pm}0.5^{circ}C$, 50 rpm for 60 minutes. The polymorphic modifications showed significant differences in the dissolution rate. The dissolution rate of Mod. 1 was faster than that of other polymorphic modifications. The transformation during storage was also studied.