The U.S. Environmental Protection Agency is currently performing a statewide monitoring survey for Temik (aldicarb) in the drinking water supplies of Florida. Prior to beginning this study, the Environmental Monitoring and Support Laboratory in Cincinnati, Ohio developed and validated the analytical procedure to be used in this study. After filtration, the water sample is directly injected into an HPLC column. After eluting from the column, the pesticide is hydrolyzed with sodium hydroxide and derivatized with o-phthaldehyde to form a fluorescent derivative. This procedure, which involves practically no sample work-up, is applicable to concentrations from below 10 micrograms/l to well over 500 micrograms/l. The procedure has been validated for aldicarb, aldicarb sulfone, aldicarb sulfoxide, oxamyl, methomyl, 3-hydroxy carbofuran, carbofuran, and carbaryl. The results of method detection limit studies and sample storage studies are presented.