Several programme offices of the United States Envirnmental Protection Agency (USEPA) have been investigating the use of immunoassay methods for environmental applications for several years, but with limited success. Most of the problems concerned method ‘rugged‐ness’ (i.e. they worked well in clean, spiked matrices, but not well on actual samples). The situation has changed significantly since January 1992, when the Office of Solid Waste received its first rugged immunoassay method (for pentachlorophenol) that worked on field samples. In the past 30 months, several more have followed. This paper addresses several major topics including: an overview of the USEPA's major regulatory programmes; how analytical methods are used in regulatory programmes and a brief overview of the regulatory approval process; general guidelines for the development of screening methods; specific validation criteria for immunoassay methods; the current status of the USEPA immunoassay method development programme; current and potential environmental applications for immunoassay technology; and barriers to implementation of immunoassay methods and the steps being taken to overcome them. The overall future of the technology for environmental monitoring and analysis looks very bright. It offers a cost‐effective way to generate reliable information on which sound environmental decisions can be based.