Results of an investigation of aerosol particles in Cape Grim (41¿S, 145¿E) for the period February 1978 to May 1980 are presented. Size distributions were obtained for radii of ~0.003 to ~5 μm. These distributions typically are bimodal in dN/d log r versis log r with modes at ~0.025 and 0.5 μm radius. No evidence was observed for a nucleus mode previously reported for this site. The aerosol consisted of three distinct fractions, a small particle fraction of ammonium sulfate, a sea-salt fraction, and a small fraction (<1%) of insoluble noncrystalline but otherwise unidentified particles.