We report the results of three validation studies for a short measure of emotional, physical, and behavioral markers of eustress and distress as they occur when individuals encounter stressful events in academic and organizational settings. Given the importance of the distinction between “positive” and “negative” stress as well as the recent resurgence of research exploring the differences between challenge and hindrance stress and between eustress and distress, it is important to put forward a short, validated scale that evaluates these constructs. Our short measure—the MEDS—therefore has important theoretical as well as practical implications. By showing that the eustress and distress subscales have adequate internal consistency and good construct and criterion validity, we open new avenues for research that extends our knowledge and understanding of the antecedents and consequences of eustress and distress. We also discuss appropriate uses of the scale in educational and organizational settings.