Amongst adults, low emotion identification skill (EIS) relates to poor emotion regulation strategies, higher rates of anxiety and depression, and higher rates of somatic illness and disease [Taylor, G. J., & Bagby, R. M. (2004). New trends in alexithymia research. "Psychotherapy and Psychosomatics", 73, 68-77]. Little research has examined EIS in adolescence and, in particular, the longitudinal impact of EIS on social support and affective experience. Six hundred and sixty-seven high school students completed measures of EIS, social support and positive and negative affects in Grade 8, and again in Grade 9. Repeated measure ANOVAS revealed that negative affect increased and positive affect decreased from Grades 8 to 9. Structural equation modelling revealed that low EIS predicted increases in fear, decreases in positive affect, and decreases in the quality and quantity of social support. Amongst boys, low EIS also predicted increases in sadness. We discuss the implications of these findings for early prevention programmes. (Contains 5 figures and 3 tables.)