As part of the OECD's Pesticide Programme, a Workshop on Avian Toxicity Testing was held in Pensacola, Florida, on 4-7 December 1994. It was jointly organised by the Society of Environmental Toxicology and Chemistry (SETAC) and the OECD. This Workshop report considers the fundamental reasons information about the toxicity of chemicals to birds is needed, and thereby identify the critical features which are essential for the tests used to generate this information;  evaluates the positive and negative features of existing test methods, and of proposed alternatives, against the required critical features;   develops proposals for the revision and development of OECD Test Guidelines for avian toxicity and avoidance tests, as appropriate; and develops a framework to govern the way these tests are requested and used in practice in risk assessment.