BACKGROUND AND OBJECTIVES: "Recovery only" ST-segment depressions are sometimes detected during an exercise treadmill test. We undertook this study in order to clarify the predictive value of exercise-induced ST-segment depression occurring in recovery only. SUBJECTS AND METHODS: The study included 931 patients who had both a sign or symptom -limited treadmill test. Of the 66 patients who demonstrated abnormal ST-segment responses, 43 experienced ST-segment depressions during exercise (Group A) and 23 displayed such responses only during recovery (Group B). RESULTS: The positive predictive value of an exercise treadmill test for significant angiographic disease in group A (81.3%) was statistically different from the predictive value in group B (30.4%). Horizontal ST-segment depression in recovery periods and female sex were statistically significant factors favoring negative coronary angiographic results. CONCLUSION: The occurrence of horizontal mild ST-segment depression during only the recovery periodgenerally represents a "false positive" response, particularly in female patients.