The interactions between halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) and acetylene (C₂H₂) are studied by FTIR spectroscopy. Results obtained in liquid cryosolutions in Kr suggest weak complex formation stabilized by H – bond. The complexation enthalpy (∼11 kJ/mol) is evaluated in a series of temperature measurements (T ∼ 120–160 K) of integrated intensity of selected bands performed in liquefied Kr. The quantum chemical MP2/6-311++G(2d,2p) calculations predict four different structures of the complex. The most stable and populated (94% at T∼120 K) structure corresponds to the H – bond between H atom of halothane and pi-electron of triple bond between C atoms of acetylene. Wave numbers of vibrational bands of the most stable structure are calculated in anharmonic approximation implemented in Gaussian program.