The pulse compression and phase conjugation characteristics of stimulated Brillouin scattering (SBS) in CS2 were investigated in a focusing geometry using an iodine laser as pumping source. The highly compressed front part of the Stokes pulse was found to have better phase conjugation fidelity than the uncompressed tail part. This result is explained by considering the difference in the interaction length and spatial structure of the front and tail parts of the Stokes pulse.