Personality traits, self-perceptions, beliefs, and feelings that accompany the Imposter Phenomenon (IP) have been identified in adults but little research with adolescents has been reported. The present research describes data from a sample of 11th and 12th graders in order to examine predictors of IP among adolescents. The participants completed measures of the IP, global self-worth, social support and self-concept. Gender differences were found in correlations between IP and Parent Support, Classmate Support, and Teacher Support. Multiple regression analyses found significant predictors of IP scores for females to be Friend Support, Classmate Support and Dependability. Only Friend Support significantly predicted IP scores for males. The unique variance explained (UVE) by each of the variables was fairly modest, suggesting that the variables are explaining a considerable amount of the same portion of the variance, particularly for females.