The purpose of this study was to assess construct validity of Coopersmith's Self-Esteem Inventory (SEI) and the newly developed Perlow Self-Esteem Scale (PSES). Although developed by Coopersmith, the SEI is not theoretically compatible with his theory. Perlow's tool was developed to measure Coopersmith's construct of Self-Esteem across four dimensions. Evidence for construct validity was obtained employing three validation techniques: comparison of known groups, comparison with known tool and analysis of factor structure. The subjects were 61 individuals who met criteria for having high self-esteem and 51 individuals who met criteria for having low self-esteem. In addition to completing the SEI and PSES, subjects were asked to complete a semantic differential designed to measure self-esteem. The results of a factor analysis for the SEI were not theoretically consistent whereas factor results indicated that the PSES demonstrated two factors which were relevant. There were significant differences between high and low self-esteem groups for both the SEI and PSES. Intercorrelations among the three scales were all significant with coefficients of r =.61 or above. Reliability alphas for both scales were above.87 and stability coefficients were r =.84 for both scales. Although the SEI and PSES overlap at r =.78, the PSES may be the better tool because of its theoretical relevance. Since this tool takes little time to administer, it may be an effective clinical instrument assuming that future construct validation work is as positive as the results of this study.