The Adolescent Discouragement Indicator (ADI) was developed to assess the Adlerian construct of discouragement. The 75-item ADI contains five subscales corresponding to the five life tasks specified in Individual Psychology and is specifically designed to pinpoint the area and degree of adolescent discouragement. Item selection was based on ratings by five prominent Adlerians and item correlation with subscale scores. Age and sex norms for the ADI were established on 225 females and 299 males 12 to 18 years of age. Findings indicate that female adolescents are less discouraged than male adolescents on all scales except the love scale and both sexes reported the least amount of discouragment on the love scale. The only significant difference among the age groups is between the 13-year-olds and the 15, 16, and 17-year-olds on the love scale. An internal consistency coefficient of .95, a 2-week test-retest coefficient of .89, and a 4-week test-retest coefficient of .92 indicates that the ADI is a reliable instrument. Negative and significant (p < .001) correlations between the ADI and Social Interest Index (Greever, Tseng, & Friedland, 1973) and between the ADI and the Social Interest Scale (Crandall, 1975) contribute to construct validity and support Adler's belief that discouragement and social interest are inversely related. Results of behavioral and academic comparisons on a sample of adolescent males (N=57) seem to indicate a link between behavior, academic performance, and levels of discouragement. Results of factor analysis and interscale correlations are presented. Implications for further research include continued validation using behavioral criteria associated with discouragement, refinement of the subscales and establishment of score ranges to indicate when an adolescent is considered discouraged.