Simple, reliable measures of the quality of the environment in which a child was reared that can be used in clinical research and practice are lacking. The reliability and validity of a global scale to retrospectively appraise the quality of that environment were examined. Fifty-three clinicians from 4 centers in Australia and 1 in Hong Kong, People's Republic of China, used the scale to rate 7 case vignettes; 4 clinicians rated 20 medical records, and 49 rated 211 subjects after clinical interviews. Interrater reliability (intraclass correlation coefficient) was 0.82 (time 1) and 0.84 (time 2) for case vignettes, 0.90 for medical records, and 0.89 for clinical interviews. Consistency in time was high (r = 0.91). Lower ratings, indicative of a less adequate environment, were associated with a clinical diagnosis of oppositional defiant or conduct disorder. Our simple-to-use scale appears to measure reliably a relevant clinical construct and fills a gap among the instruments available. Ratings may be useful as a cost-effective index to consider in outcome studies, when examining response to treatment, or in other clinical research.