An experimental study of the transverse injection of a particle laden liquid jet into a supersonic air stream was conducted. Five micron diameter silicon dioxide particles with a specific gravity of 2.35 were suspended in water and injected across a Mach 3.0 air stream. A stagnation pressure of 4.2 atm. and a stagnation temperature of 15° C were maintained throughout the tests. Particle loadings of up to 68% by mass were injected. The penetration and behavior of the jets were examined through a light extinction survey and through a series of streak arid nanoflash photographs. Some of the particles were found to agglomerate into clumps ranging up to 40 microns in diameter. The clumps separated from the liquid plume and penetrated up to 45% further into the air stream than the liquid. For mass loadings greater than 55%, the jet column appeared more rigid than those of lower or zero particle loadings.