A technique of diffusive gradients in thin films with ciprofloxacin-molecularly imprinted polymers as the binding agent was developed for in situ selective sampling and measurement of ciprofloxacin in water. The ciprofloxacin uptake by the method increased linearly with time (r = 0.998) with a recovery of 96.8% in synthetic solution. The method performance was not dependent on solution pH over the pH range of 2-11 and ionic strength range from 1 × 10 to 0.5 mol/L sodium nitrate. The binding agent has a higher adsorption affinity for ciprofloxacin than for other drug residues, such as norfloxacin, chloramphenicol, and malachite green. The concentration of ciprofloxacin in river water determined by this method was 0.52 ± 0.3 μg/L, and the recoveries of ciprofloxacin were 96.1-102.0%.