A review of recent progress on particle formation in gases for synthesis of materials is given focus in the session Particle Formation in Gases at the First International Forum on Particle Technology held in Denver, CO, in August 1994. Most of the papers dealt with powder synthesis from gases and, to a lesser extent, from suspended droplets. Major advances were reported on particle formation in flames, spray pyrolysis, agglomerate dynamics, reactor design and on formation of solid powders from sprays. This article summarizes the proceedings of the above session and highlights the most important results as they came across at the ensuing discussions.