We examined the daily dynamics among self-concept clarity and identity processes, and their effects on distress, among a sample of 580 Dutch adolescents. Participants completed measures of identity, self-concept clarity, anxiety and depression at annual intervals; and daily single-item measures of self-concept clarity, identity commitments and reconsideration across three 5-day weeks. We examined (a) cross-lagged associations of self-concept clarity to identity commitment and reconsideration and (b) associations of daily fluctuations in self and identity processes to later anxiety and depression. Results indicated that self-concept clarity and identity commitments influence one another reciprocally across days, and that day-to-day fluctuations in identity predicted later anxiety and depression. Results are discussed in terms of self and identity processes and their effects on distress. © 2010 John Wiley & Sons, Ltd.