CO, HCO+ and NH3 observations have been carried out towards the high latitude cloud L1642 using the 1.2-m GISS, the 11-m NRAO, the 14-m Metsähovi and the 100-m Effelsberg radio telescopes. The velocity field of the CO gas indicates a core-halo structure. The core component has a constant radial velocity, whereas the halo gas is slightly (> 1 km/s) redshifted, as compared to the radial velocity of the core, and shows velocity gradients towards the cloud edges in a similar way as the HI gas associated with L1642. Within the border of the 13CO emission the mass of the cloud is estimated to be some 76M⊙. In contradiction to Magnani et al.(1985), who claimed that L1642 belongs to a population of very young high latitude clouds which are breaking up, this study supports the view that L1642 is in virial equilibrium and significantly older than 106 yr. The virial equilibrium of L1642 enables a distance determination of ˜ 190 pc to the cloud core.