Solvation dynamics of 4-aminophthalimide (4-AP) is studied in a Triton X-100 (TX) micelle at three different temperatures. The average solvation time <tau(s)> has been found to be 800, 400 and 110 ps at 283, 303 and 323 K, respectively. This corresponds to an activation energy of 9 +/- 1 kcal mol(-1). The observed temperature dependence is in qualitative agreement with recent computer simulations on the solvation dynamics in micelles. (C) 2004 Elsevier B.V. All rights reserved.