  We have observed the radio source NGC 3862 (3C264) simultaneously with the
EVN and the MERLIN arrays, obtaining detailed images of its radio structure
from parsec to sub-kiloparsec scales. 3C264 shows a one-sided jet, with evident
variations in its morphological properties with distance. We have analyzed HST
optical data of NGC 3862 finding a one-to-one correspondence between radio and
optical features in the jet. The radio to optical spectral index is
approximately constant along the jet. Synchrotron appears as the most plausible
mechanism for the observed jet emission at radio and optical wavelengths. Local
particle reacceleration or, alternatively, deviation from the condition of
equipartition, are plausible mechanisms to explain the low synchrotron cooling
and constant spectral index in the jet of 3C264.
