The potential use of planar laser-induced fluorescence (PLIF) of sulfur dioxide (SO2) for visualization of exhaust-gas distributions is outlined and demonstrated. Strong absorption features in the UV spectral range allow excitation of SO2 with the fourth harmonic of a Nd:YAG laser at 266 nm. Fluorescence emissions are mostly red-shifted and can be easily detected in single-shot imaging arrangements with a good signal-to-noise ratio. This study uses a premixed methane/air flame that is doped with SO2 to demonstrate the technique. The signal strength has a pronounced temperature dependence for excitation at 266 nm.