Bacterial diseases are common in captive cranes. Administration of antimicrobial drugs in the drinking water could provide a nonstressful means of treatment in these birds. This preliminary study was conducted to determine if therapeutic plasma concentrations of enrofloxacin, its primary active metabolite ciprofloxacin, or both, could be achieved and maintained in sandhill cranes (Grus canadensis) after administration in drinking water at a concentration of 50 ppm. Drinking water medicated with enrofloxacin was provided ad libitum to 8 healthy sandhill cranes (4 housed individually and 4 housed in pairs) for 14 days. Mean enrofloxacin plasma concentrations (±SD) were 0.03 (±0.02), 0.03 (±0.02), 0.02 (±0.01), and 0.01 (±0.00) μg/ml on days 2, 6, 10, and 14, respectively. Mean ciprofloxacin plasma concentrations paralleled those of enrofloxacin but were slightly lower, ranging from 0.01 to 0.02 μg/ml. Enrofloxacin and ciprofloxacin concentrations both were below accepted therapeutic plasma concentrations for birds. Based on the plasma concentrations achieved in this preliminary study and the minimum inhibitory concentration values for bacteria commonly isolated from poultry species, enrofloxacin-medicated water would only be effective for treating infections of highly susceptible bacteria in sandhill cranes.