In this study, Al-MgO reinforced metal matrix composites of 5%, 10% and 15% reinforcement-volume ratios were produced by melt-stirring and subjected to machining tests by carbide and coated carbide cutting tools. Machining tests were conducted with 150, 200, 250 and 300 m/min cutting speeds, 0.075, 0.15 and 0.225 mm/rpm feed rates and 1 mm depth of cut. Piezoelectric quartz crystal type dynamometer was used to measure cutting forces. As a result of the tests, it was observed that the increase in cutting speed first led to an increase and then a decrease in main cutting force values (Fc), and the increase in feed rate was accompanied with increased main cutting forces. The most consistent results in terms of Fc values were displayed by 10% MgO reinforced composites. While no abrasion occurred on the surfaces of cutting tools, build up edge formation was observed in the machining tests.