Neutron-diffraction techniques have been used to study the magnetic ordering of the Nd ions in semiconducting Nd2CuO4 and superconducting Nd1.85Ce0.15CuO4. For the Ce-doped system a sharp transition to long-range antiferromagnetic order occurs at TN1.2 K, with a simple magnetic unit cell which is double the chemical unit cell along the a and b directions. The same magnetic structure is observed in the parent system Nd2CuO4, in which the Cu spins are also ordered magnetically, but strong coupling between the Nd and Cu sublattices is indicated. © 1990 The American Physical Society.