Successful fabrication of thin In0.1Ga0.9As strained quantum wires by a metalorganic chemical vapor deposition selective growth technique is reported. The In0.1Ga0.9As strained quantum wires fabricated here are triangular-shaped with a lateral dimension of less than 40 nm. In addition, the selective growth behavior of InGaAs was investigated using dot structures on SiO2-patterned GaAs substrate changing substrate temperature, V/III ratio, and alloy composition of In. The results show that the growth behavior of InGaAs is similar to that of GaAs, indicating that the same growth technique as that for the GaAs quantum wires can be applied to the growth of InGaAs quantum wires.