The effect of perception of problem relevancy on postformal reasoning performance of two groups of adolescents (13 to 16 years and 17 to 19 years) and one group of young adults (20 to 29 years) was examined. Problems known to reflect issues and situations relevant to adolescents, adults, and older adults were presented to 105 subjects. The three age groups did differ with respect to their perception of problem relevancy. Further, perceived relevancy appeared to disrupt postformal reasoning among the youngest group of adolescents while facilitating performance among the young adults. These results are discussed in relation to previous findings by Blanchard-Fields (1986) and theoretical positions postulating the development of postformal reasoning. Implications for effective counseling of adolescents are considered.