Determination of lead poisoning problem areas is complicated by the nature of the disease process. Rigorous documentation of lead poisoning as a cause of mortality in birds requires the integration and evaluation of pathological and toxicological data by an experienced diagnostician. No single technique provides unequivocal proof that lead exposure occurred at the site of death. However, evaluation processes that integrate knowledge regarding the course of lead poisoning in birds, bird movement patterns in specific geographic areas, and findings from studies involving criteria commonly used to measure exposure to lead shot provide a sound basis for determination of specific problem areas. Sequential sampling during the period of bird use is an important requirement for establishing strong cause and effect relations. Knowledge of lead poisoning characteristics as a disease process are also useful in identifying lead poisoning problem areas.