The jet of 3C273 is the only quasar jet visible at both radio and optical wavelengths. Investigations using ground-based observations suggest that the optical emission, like the radio, is produced by the synchrotron process. We present here a new radio map at 18 cm wavelength made with the improved MERLIN array (Fig. 1b) and compare it with a new optical image obtained with WFPC2 on the Hubble Space Telescope (Fig. 1a) This work has been carried out in collaboration with colleagues from Princeton, Pennsylvania State University and Caltech and is being published by Bancall et al. (1995).