Due to the increasing consumption of fossil fuels, alternative fuels in internal combustion engines have attracted a lot of attention in recent years. Ethanol is the most common alternative fuel used in spark ignition (SI) engines due to its advantages of biodegradability, positively impacting emissions reduction as well as octane number improvement. Meanwhile, acetone is well-known as one of the industrial waste solvents for synthetic fibers and most plastic materials. In comparison to ethanol, acetone has a number of more desirable properties for being a viable alternative fuel such as its higher energy density, heating value and volatility. In order to investigate the combustion, performance and emission characteristics by using acetone-gasoline blends in a port-fuel injection (PFI) spark-ignition (SI) engine, the various fuel blends of AC0 (gasoline), AC10 (90% gasoline and 10% acetone by volume), AC20 (80% gasoline and 20% acetone by volume) were tested, and the experiments were conducted at the engine speed of 1200 RPM and loads of 3 and 5 bar brake mean effective pressure (BMEP) under different equivalence ratios (Φ=0.83-1.25). The performance of these blends was evaluated through measurements of engine torque, in-cylinder pressure and exhaust emissions. In addition, the effect of acetone addition on the aromatic hydrocarbons emissions was also investigated by using a gas chromatography coupled to a mass spectrometer (GC/MS) for identification and a gas chromatography with a flame ionization detection (GC/FID) for quantification.