Ciprofloxacin (CfH, C17H18FN3O3) crystallizes with 2-thiobarbituric (H2tba) and barbituric acid (H2ba) in the aqueous solution to yield salt CfH2(Htba)·3H2O (1), salt cocrystal CfH2(Hba)(H2ba)·3H2O (2), and salt CfH2(Hba)·H2O (3). The compounds are structurally characterized by the X-ray single-crystal diffraction. The numerous intermolecular hydrogen bonds N–H⋯O and O–H⋯O formed by water molecules, Htba−/Hba− and CfH2 + ions, and H2ba molecules stabilize the crystal structures of 1 to 3. Hydrogen bonds form a 2D plane network in the salts of 1 and 3 and a 3D network in the salt cocrystal of 2. There are different π-π interactions in 1 to 3. The compounds have been characterized by powder X-ray diffraction, thermogravimetry/differential scanning calorimetry, and Fourier transform infrared spectroscopy. The compounds dehydration ends at 130°C to 150°C, and their oxidative decomposition is observed in the range of 250°C to 275°C.