Coherent low frequency (100-125 cm(-1)) nuclear motion was detected in the cis --> trans condensed phase isomerization of stilbene. A mode, associated with phenyl torsional motion, has a vibrational dephasing time of 100 fs and exhibits solvent-dependent wavepacket dynamics. Selective probe wavelengths (600, 650 and 690 nm) exhibit phase shifts for the wavepacket dynamics that are also solvent sensitive.