A longitudinal cross sectional study of Hospital Emergency Department (HED) procedures over a nine month period was conducted. A total of 1,541 procedures were observed on 56 randomly selected 8-h work shifts. Shifts were distributed: 34% day shift; 34% evening shift; and 32% on the night shift. Observations on the evening shift were oversampled to capture an adequate number of trauma patients. Observations were distributed: 33% day shift; 39% evening shift; and 28% on the night shift. Measurements included: type of procedure; adherence to specific barrier technique, i.e., use of gloves, gowns, masks, and eye protection; and occurrence of adverse exposure. Ten types of HED procedures were documented and analyzed. Computerized tracking of study observations established periodic rates of HED health care worker (HCW) adherence to universal precautions. These data are important for internal quality control/assurance programs and rate comparisons within and across institutions over time. The longitudinal evaluation of the database revealed that glove compliance increased over the period of the study and adverse exposure decreased. Conducting ongoing or periodic observational studies of this kind are important and necessary in order to gauge HED response to the epidemiologic challenges of urban society.