The stricter legislation on exhaust emissions and growing demands for the use of alternative fuel requires the investigation of various blends in terms of combustion, emissions and efficiency in gasoline engines. Bioethanol–gasoline blends represent a particularly promising direction in reduction of traffic pollution which represents a major part of green-house gases. Bioethanol has a higher octane number and oxygen implying several advantages compared with gasoline in internal combustion engines. The aim of this paper is to study and analyze emissions of different blends of bioethanol–gasoline in a six cylinder gasoline engine in laboratory condition. The use of bioethanol blends decreases the CO and HC emissions and increase brake power and torque.