Quantum ignition of intramolecular rotation may be achieved as follows: first, a few-cycle infrared (IR) laser pulse excites the torsional vibration in an oriented molecule. Subsequently, a well-timed ultrashort ultraviolet (UV) laser pulse induces a Franck-Condon type transition from the electronic ground to the excited state with approximate conservation of the intramolecular angular momentum. As a consequence, the torsional motion is converted into a unidirectional intramolecular rotation, with high angular momentum (approximate to 100h). The mechanism is demonstrated by means of representative laser driven wave packets which are propagated on ab initio potential energy curves of the model system (4-methyl-cyclohexylidene)fluoromethane. (C) 2004 Elsevier B.V. All rights reserved.