Immunoassay is recognized as a promising method for screening environmental contaminants. The article deals with principles and practical applications of immunochemical methods in pesticide analysis. An overview is given of organochlorine and carbamate pesticides for which immunoassays, in particular the ELISA test, were developed, including commercially available kits. In addition, a survey is given on further developments of existing or new immunoassays and on the application of immunochemistry in other fields (immunoafinity chromatography, immunosensors).