Ion implantation of Cr at concentrations of 3 and 5 atom % was performed in AlxGa1-xP:C (x=0,0.24,0.38) epi layers grown by gas source molecular beam epitaxy. No second phases were detected by both X-ray diffraction and transmission electron microscopy. Ferromagnetic ordering to 300 K was observed in superconducting quantum interference device (SQUID) measurements, comparable to similar samples using Mn as the dopant. As well, calculated saturation moments are found to lower for Cr-implanted materials than Mn-implanted materials. As the Al fraction in the ternary starting material is increased, the saturation moments are found to decrease. Based upon this evidence, Cr does not appear to be an advantageous choice compared to Mn for high-temperature ferromagnetism in AlGaP. (C) 2004 The Electrochemical Society.