||Results of structural, magnetic and heat capacity studies are reported for the REInAu2 series (except europium). A crystallographic transformation from cubic to tetragonal structure occurs for the compounds with lanthanum, cerium, praseodymium and neodymium. With the exception of LaInAu2, the phase transition has no observable effect on the magnetic susceptibility. Compounds formed with gadolinium, terbium, dysprosium and holmium order antiferromagnetically at low temperature. In this series YbInAu2 is confirmed to be in an unstable valence state with the maximum 2J + 1 = 8 ground state degeneracy.