CBrz has been produced by pyrolysis in a supersonic free-jet expansion and investigated by laser-induced fluorescence-excitation spectroscopy. Observations of the vibrational isotope effect for several bending progressions have led to a reassignment of the earlier gas-phase UZ' numbering and have consequently cleared up some earlier discrepancies. For the 79BrC81Br species, values of several vibrational frequencies (referred to the lowest vibrational level of each electronic state) are uy = 475 cm-l, u : = 185 cm-l, and u y = 599 cm-l; and the origin of the A 'B1 -X 'A1 electronic transition is placed at TOO = 15 091.5 cm-l. Partially resolved rotational sub-band structure yields so-me structural results. In particular, the BrCBr bond angle increases 21" upon excitation from the X to the A state. The electronic origins, TOO, and the argon matrix shifts of TOO, are shown to satisfy physically reasonable additivity relationships for CBrz, CC12, and CBrCl.