A summary of some recent results of neutron scattering studies of high temperature superconductors is given, with a focus on resonant spin excitations in the superconducting states of YBa2CU3O6+x and Bi2Sr2CaCu2O8+delta. The opportunities offered by advances in neutron scattering instrumentation, such as focusing and polarization techniques, for these experiments are discussed, (C) 1999 Published by Elsevier Science Ltd. All rights reserved.