Permanent magnets based on the compositions Pr15Fe79B6, Nd15Fe79B6, Pr15Fe62.5Co16Al1B5.5, and Nd15Fe62.5Co16Al1B5.5 have been fabricated employing conventional powder metallurgical processes. Proper heat treatment has been found to improve magnetic properties. For example, in magnets of composition Pr-Fe-Co-Al-B, the heat treatment optimized in this study improved Br and (BH)max by about 5% and 10%, respectively, in comparison with conventional heat treatment reported in the literature. The temperature coefficients of magnetic properties have also been improved through Co and Al substitutions.