The complete vibrational spectra of α-bromoacetaldehyde dimethyl acetal and α-bromoacetaldehyde dimethyl s6 have been recorded on the pure liquids, and a tentative vibrational assignment has been proposed. The infrared spectra of both compounds in the crystal state have also been recorded at low temperatures. There is no apparent evidence of a conformational equilibrium in the liquid phase. The infrared spectra of three other acetals have been recorded, and the data from all of the compounds are discussed in terms of previously proposed group frequencies of acetals in both the infrared and Raman.