With the increase of ecology standards, implementation of gaseous fuels is being studied. One of the most researched alternative fuels, due to its widespread availability and low cost is natural gas. It has been shown that the use of natural gas as a transportation fuel implies many improvements in terms of emissions. Due to the higher efficiency of compression ignited engines, implementation of natural gas in compression ignited engines is being studied. However, because of the high octane rating of natural gas, a small amount of high cetane fuel must be used to ignite the mixture. The engine then uses different fuels at the same time and is called a dual fuel engine. The objective of this thesis is to setup and study the diesel-methane dual fuel engine. An existing diesel engine has been converted to be able to run in the dual fuel operating mode. After the successful conversion, influences of the mass of injected diesel fuel, of the injection timing, of injection pressure and of engine speed on engine performance and emissions have been studied. It has been found that good combustion stability and lower emissions can be achieved at mid and high load with an optimum combination of engine parameters. On the other hand, operation under low load is characterized with unstable combustion coupled with low efficiency and high HC and CO emissions.