High‐quality InAlAs with excellent photoluminescence and low electron concentrations has been grown by organometallic vapor phase epitaxy (OMVPE). For InAlAs lattice matched to InP, electron concentrations as low as 7×1015cm−3and mobilities as high as 4472 cm2/V s at 300 K have been achieved. These values are comparable to results measured on material grown by liquid phase epitaxy and molecular beam epitaxy and exceed results for previously published OMVPE grown material. The variation of the structural, optical, and electrical properties of the InAlAs with lattice mismatch is reported.