Though radiocolloids have been used for over twenty years in the treatment of ovarian cancer, no comprehensive review of the literature exists. This review incorporates the historical development of radiocolloids, discusses the physical properties and physics of the two commonly used colloids, radioactive gold (Au-198) and radioactive phosphorus (P-32), discusses instillation and distribution of intraperitoneally administered P-32, and reviews result of treatment. The conclusions reached from this review are that Au-198 is a very different radiocolloid than P-32; that the dose of clinically used P-32 is determined from an empirically determined dose of Au-198; and that the dose of 100 mCi to 150 mCi of Au-198 yields significantly greater radiation than 10 mCi to 15 mCi of P-32. The complications associated with Au-198 are results of a possibly excessive dose, with a significant gamma component, delivered over a shorter period of time. It is clear that in greater than 99% of distintegrations each beta particle is associated with a gamma component. The review of the literature also shows that no propsective randomized well controlled study has indicated the effectiveness of P-32 over other treatment modalities. The clinical applicability of P-32 awaits prospective randomized trials and the ability to accurately determine dose and dose-distribution in-vivo.