© 1992 SPIE. All rights reserved. This paper provides a brief overview of the development and application of fiber-optic antibody-based fluoroimmunosensors (FIS) for measuring environmental pollutants and related biomarkers of human exposure and health effects. The FIS combines the excellent specificity of the antigen/antibody reaction, the high sensitivity of laser excitation, and the versatility of fiber-optics technology. Various types of FIS devices were also used to detect toxic chemicals (such as benzo-a-pyrene) and related DNA adducts (e.g., benzo()pyrene tetrol).