Heat capacity, magnetic susceptibility, and electrical resistivity measurements have been made on a wide ranging set of Ce‐La and Nd‐La alloys. In the case of Ce it is found that less than 5 at. &percent; of La will prevent the &bgr; (dhcp) to &agr; (collapsed fcc) transition atT≲50 K. In the case of Nd‐La only the dhcp allotrope is formed. Two magnetic ordering temperatures have been found for many of the samples. These are believed to be caused by antiferromagnetic ordering on the two different atomic sites in the dhcp structure, cubic and hexagonal. In both sets of alloys the two ordering temperatures coalesce into one for La concentrations ≳30&percent;. Additional magnetic features in Ce‐La alloys are explained by the formation of the fcc phase.