The guidelines provided in this document were developed for use in evaluating sediments throughout Ontario, and replace the Open Water Disposal Guidelines (published by the Ministry in 1976) currently used for sediment evaluation. The Provincial Sediment Quality Guidelines (PSQGs) are intended to provide guidance during decision-making in relation to sediment issues, ranging from prevention to remedial action. The document provides a background to the PSQG development, the PSQGs, the application of the guidelines to sediment evaluation and the protocol used in establishing the guidelines. Companion volumes to the document (Jaagumagi 1992a, 1992b) provide more details on the actual derivation of the numeric values for various parameters.