We report the growth of InP self-assembled quantum dots (QDs) on In0.5Al0.5P and In0.5(Al0.6Ga0.4)0.5P matrices, lattice matched on 0°, 2°, 6°, and 25° off-axis (100) GaAs substrates by metalorganic chemical vapor deposition. The influence of the substrate misorientation on the morphology and cathodoluminescence (CL) properties of the InP QDs was investigated. We find that the density of QDs grown on both In0.5Al0.5P and In0.5(Al0.6Ga0.4)0.5P matrices increases with the misorientation angle up to 6° off (100). At the same time, the dispersion of the QD size is getting larger for the growth on an In0.5Al0.5P matrix, but not for the growth on an In0.5(Al0.6Ga0.4)0.5P matrix. The InP QDs grown on In0.5(Al0.6Ga0.4)0.5P on 25° off-axis substrates are two-dimensionally well ordered. Moreover, the ordering improves and the density of QDs increases with an increase in the deposition of InP. The room-temperature CL intensity of InP QDs grown on a 25° off In0.5(Al0.6Ga0.4)0.5P is much stronger than that for InP QDs grown on a 25°-off In0.5Al0.5P matrix. © 2003 American Institute of Physics.