Bio-butanol has been widely investigated as a promising alternative fuel. However, the main issues preventing the industrial-scale production of butanol is its relatively low production efficiency and high cost of production. Acetone-butanol-ethanol (ABE), the intermediate product in the ABE fermentation process for producing bio-butanol, has attracted a lot of interest as an alternative fuel because it not only preserves the advantages of oxygenated fuels, but also lowers the cost of fuel recovery for individual component during fermentation. If ABE could be directly used for clean combustion, the separation costs would be eliminated which save an enormous amount of time and money in the production chain of bio-butanol. In this respect, this study is focused on investigating the regulated and unregulated emissions of a single cylinder port-fuel injection spark ignition engine fueled with ABE and gasoline blends. 30 vol.% ABE fuels with different component volumetric ratios (A:B:E of 3:6:1 and 6:3:1) were blended with 70 vol.% gasoline, which were represented as ABE(361)30, ABE(631)30 respectively, were tested. Experiments were conducted at an engine speed of 1200 rpm, and at engine loads corresponding to brake mean effective pressures (BMEP) of 3 bar and 5 bar and under various equivalence ratios (Φ=0.83-1.25). Exhaust gases were measured including nitrogen oxides (NOx), carbon monoxide (CO) and unburned hydrocarbons (UHC). Additionally, aromatic hydrocarbons emissions such as benzene, ethylbenzene, toluene and xylenes (BTEX) concentrations were also measured by a gas chromatograph coupled with a mass spectrometer (GC/MS) and a gas chromatograph with a flame ionization detection (GC/FID).