Abstract: Micro powder injection molding (μ-PIM) was studied to manufacture micro-sized gearwheels of iron. Carbonyl Fe powder with a mean size of 2.3 μm and wax-based thermoplastic binder mixture were used in the manufacture process. When the powder loading was fixed as 58%, the molded compact of a gearwheel whose addendum circle diameter is 700 μm was obtained with well shape retention. The profile of the gearwheel and the roundness of the centre hole were kept well after sintering. The sintering shrinkage of the addendum circle is 15.6% and the roughness of the gearwheel surface is S_a=5.099 μm.