The effects of a wide variety of fuel types on the gaseous exhaust emissions, smoke, and particulates and on the combustor wall temperatures of a small industrial gas turbine engine are presented. The results were determined from evaluation tests conducted with the use of a single-shaft, constant-speed engine, rated at 534 kW, which employs a single, can-type combustor. The test fuels included a pure hydrocarbon, aviation gasoline, jet fuels, diesel fuel, fuel oils, an experimental broad-specification fuel, and a coal-derived fuel from the solvent-refined coal II (SRC-II) process. The hydrogen content of the fuels ranged from 9.1 to 16.1% by weight. Decreasing the fuel hydrogen content increased smoke emissions and combustor wall temperatures. The relationship between the mass concentration of exhaust particulates and the smoke number was similar for the coal-derived SRC-II and petroleum-based fuels. The combustion efficiency, determined from exhaust hydrocarbon and carbon monoxide emissions, did not change appreciably at any load condition for a wide range of fuel properties. The conversion of fuel-bound nitrogen to exhaust nitrogen oxides (NOx) was found to depend on the fuel nitrogen content and engine load. The conversion efficiencies were similar for the coal liquid, which was naturally high in fuel-bound nitrogen, and an artificially doped petroleum fuel.