Direct fabrication of thin-wall metallic parts by low-power laser cladding is developed. With some assumptions for fabrication of thin-wall metallic parts with a focused Gaussian laser beam, theoretic models of the minimum laser power and of wall thickness are established, and effects of process parameters on the minimum laser power and wall thickness are analyzed. In the presented experiment, a CO2 laser with low power and a small light spot on the interacting area are applied in single-pass cladding. The experimental results demonstrate that if the scanning velocity, powder flow rate, and other process parameters are matched suitably with the laser, a thin wall with thickness down to 0.4 mm can be formed and that the thickness of the wall formed by single-pass cladding is dependent on the process parameters and the wall height.