This study tested the validity of the Haan (1965) psychological defense scales, which have shown promise for clinical and research assessment. Three subject samples participated: ex-inpatients (n = 80) from a longitudinal high-risk project, their spouses (n = 104), and private college students (n = 124). Valid defense scales were predicted to show a specific pattern of correlations with MMPI ego-strength and standard scales across all three cohorts, with measures of symptoms among the ex-inpatients, and with overall severity of pathology for all groups in a pattern consistent with Vaillant's defense model. The regression scale showed excellent validity, and projection received equivocal support, but the other scales were not validated. Denial appeared to reflect psychological health.