The effects of domperidone, scopolamine butylbromide and cimetidine on the absorption and bioavailability of ciprofloxacin were studied in female rats. Ciprofloxacin was given in a single oral dose of 30 ㎎/㎏ to control group. Ciprofloxacin was concurrently administered with domperidone (T₁ group), scopolamine butylbromide (T₂ group), and cimetidine (T₃ group) to rats, respectively. Significantly changed pharmacokinetic parameters observed in T₂ group when compared with control group were first-order absorption rate constant, Ka(4.43±0.85 versus 2.86±0.41 hr^(-1), p<0.05), time needed to reach peak concentration, T_(max) (32.27±2.46 versus 51.75±5.51 min, p<0.05), area under the plasma concentration-time curve, AUC (332±19 versus 477±27 ㎍·min/㎖, p<0.05) and absolute bioavailability, Fabs (60.6±3.6 versus 87.0±5.0%, p<0.05). On the other hand, domperidone and cimetidine did not significantly affect the absorption of ciprofloxacin. It is suggested that when scopolamine butylbromide is selected for clinical use, there is need for awareness of the reduction in absorption rate and the enhancement in absorption extent of ciprofloxacin.