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. Copyright © 2010 John Wiley & Sons, Ltd.