The photodissociation of triiodide into diiodide and iodine in ethanol solution was studied by a novel femtosecond pump-probe technique. The dispersed emission of the triiodide sample was recorded as a function of the delay between a 407 nm pump pulse and a 815 nm probe pulse. The most prominent feature of the resulting time dependent spectra is a strong anti-Stokes (with respect to the probe wavelength) contribution. This contribution rises with a delay of similar to500 fs and decays on the 2 ps time scale. The decay of the anti-Stokes spectrum is discussed in terms of the cooling dynamics of nascent diiodide for which the technique presented here gives a more direct access than transient absorption spectroscopy.