Oil is one of the main energy sources used in internal combustion engines. The high level of environmental pollution, continuous limitation of emission rates, increasing environmental awareness, and uncertainty in oil prices, have been driving the energy world to alternative fuels for the last decades. In this study, ethanol and acetylene have been suggested as alternative fuels to gasoline since they can be produced from non-petroleum resources and the effects of gasoline, ethanol and acetylene on the emission parameters and engine performance of a spark-ignition engine were investigated. The experiments have been carried out under 25% and 50% constant loads at 1500 rpm and different excess air ratios. The engine used in the experiment is a four-cylinder, four-stroke and water-cooled internal combustion engine. When using ethanol and acetylene, UHC and NO emissions significantly reduced compared to gasoline. As a result of the experiments, it was observed that acetylene have better thermal efficiency and emission values than that of gasoline and ethanol in high EAR values.