We study the transient photophysical properties of a diarylethene with a carboxylic anchor group by a combination of steady-state and ultrafast emission and absorption spectroscopy. After excitation of the closed-ring form, fluorescence with a quantum yield of 10 (5) is observed and separated into different spectro-temporal components. The S-1 state of the closed-ring form shows a lifetime of 1.3 ps and decays mainly by internal conversion to the S-0 state of this isomer. This vibrationally hot ground state cools on a time scale of 10 ps. (C) 2012 Elsevier B. V. All rights reserved.