The precision and accuracy of two Kodak Ektachem DT-60 portable blood analyzers were assessed in a model (research) cholesterol screening program in Rochester, New York. Between June and October 1987, a total of 8,573 people underwent a cholesterol screening held in a movable trailer. A wide variety of temperature, humidity, and other potentially adverse conditions were encountered during the screening period. Between-run coefficients of variation ranged from 1.9 percent to 4.8 percent per month; average bias compared to a Reference Laboratory method ranged between +0.2 percent and +2.0 percent. Both precision and accuracy met currently recommended standards for cholesterol testing in the United States.