We report on synthesis and magnetic characterization of the tetragonal ThCr 2 Si 2 -type PrIr 2 Si 2 and NdIr 2 Si 2 compounds. The PrIr 2 Si 2 compound, not yet signaled, orders antiferromagnetically below T N =47(1) K. The NdIr 2 Si 2 compound orders antiferromagnetically below T N =33(1) K. The magnetic structure of NdIr 2 Si 2 consists of ferromagnetic Nd planes antiferromagnetically coupled with the next adjacent Nd plane stacked along the c axis. The results are discussed and compared with those obtained previously on isotypic RT 2 Si 2 compounds (R=Pr-Nd; T=transition metals of groups 7-9).