The proceedings of the "International Conference on Spin Observables of Nuclear Probes" are presented in this volume. This conference was held in Telluride, Colorado, March 14-17, 1988, and was the fourth in the Telluride series of nuclear physics conferences. A continuing theme in the Telluride conference series has been the complementarity of various intermediate-energy projectiles for elucidating the nucleon-nucleon interaction and nuclear structure. Earlier conferences have contributed significantly to an understanding of spin currents in nuclei, in particular the distribution of Gamow-Teller strength using charge-exchange reactions. The previous conference on "Antinucleon and Nucleon Nucleus Interactions" compared nuclear information from tra tional probes to recent results from antinucleon reactions. The 1988 conference on Spin Observables of Nuclear Probes, put special emphasis on spin observables and brought together experts using spin information to probe nuclear structure. Spin observables have provided very detailed information about nuclear structure and reactions. Since the 1985 Telluride conference we have seen data from new focal plane polarimeters at LAMPF, TRIUMF, IUCF and elsewhere. In addition, spin observables provide an important common ground between electron and hadron scattering physics. In the future we look forward to new facilities such as NTOF for polarized neutron measurements at Los Alamos and a vigorous spin program at CEBAF.