The objective of this study is to experimentally investigate the mechanisms in machining of aluminum/silicon carbide (SiC) composite with two types of diamond whiskers. These whiskers are prepared from polycrystalline diamond compacts (PDC) and chemical vapor deposition (CVD) diamond plates which are cut into dimensions of 10×0.3×0.6 mm with an Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser. In order to obtain sharp and consistent cutting edges, the diamond whiskers are polished with diamond powders of the average grain sizes of 10 µm, 2.5 µm and 1 µm, respectively. A precision grinder is used to conduct machining of the aluminum/SiC composite at a depth of cut smaller than that in the conventional milling but larger than the individual grit depth of cut in grinding. Scanning electron microscopy (SEM) is utilized for observing the machined workpiece surfaces, the whisker cutting edges, and a surface profilometer for inspecting surface roughness and verifying the actual depth of cut in the machined workpiece. The study discusses the mechanisms of workpiece material removal and diamond whisker wear in machining of the aluminum/SiC composite.