While fluoroquinolones are widely used in the treatment of various infectious disease, not enough attention has been paid to their adverse effects on salivary glands functions. In the present study, the effects of ofloxacin, a fluoroquinolone antibiotic, on rat parotid and submandibular gland functions, were examined in an acute experiment. Ofloxacin (OFLX) was administered intraperitoneally at various doses (20, 40, and 80 mg/kg). Pure parotid and submandibular saliva were collected intraorally by microployethylene tubes under anaesthesia using a dissecting microscope. Flow rate, amylase activity, total protein, and calcium concentrations were reduced by all doses of OFLX (20, 40, 80 mg/kg, P < 0.01) in parotid saliva. In parotid saliva, sodium and potassium were increased by doses of 20 and 40 mg/kg (P < 0.01) and 20, 40, 80 mg/kg (P < 0.01) respectively. In submandibular saliva, flow rate, total protein and calcium concentrations were significantly reduced by all doses (20, 40, 80 mg/kg, P < 0.01). Sodium and potassium concentrations were also increased by a dose of 80 mg/kg, (P < 0.05) in submandibular saliva. It is concluded that ofloxacin inhibits rat salivary gland functions, which might be observed as a side-effect in humans. Properties of fluoroquinolones to alter intracellular cAMP and calcium levels and their ability to suppress DNA, RNA and protein synthesis of acinar cells might be possible reasons for the observed changes.