There is growing evidence of a functionally significant link between the perifornical region of the lateral hypothalamus (PFH) and the mesoaccumbens dopamine projection. The present study assessed the ability of intra-accumbens dopamine receptor blockade, firstly to impair the locomotor stimulant properties of intra-PFH sulpiride, and secondly the ability of intra-PFH sulpiride to support a conditioned place preference. Locomotor activity and conditioned place preference training were assessed using an apparatus consisting of three distinctive compartments. Following a pre-exposure session in which groups showed equivalent preference for the three compartments, conditioned place preference training was carried out over five drag (0, 0.03 or 0.1 jig Intra-accumbens sulpiride; 0 or 5üg intra-PFH sulpiride) and five vehicle sessions. For each animal, drug and vehicle treatments were randomly paired with one of the two outermost compartments. Locomotor activity was monitored during each session. Intra-PFH sulpiride alone increased locomotor activity during later sessions, and this gradual increase in locomotor response, relative to vehicle infusions, was blocked by intra-accumbens sulpiride co-infusion. On the final drug-free test day for conditioned place preference, animals were again permitted free access to all three compartments, and the time spent in each was compared with that on initial exposure. Intra-PFH sulpiride alone supported a conditioned place preference. Intra-accumbens sulpiride was without intrinsic effect, but nevertheless blocked the ability of intra-PFH sulpiride to support a conditioned place preference. These data provide further support for a functionally significant link between the PFH and mesoaccumbens dopamine projection, with regard to the locomotor stimulant properties and ability of intra-PFH infusions of sulpiride to support a conditioned place preference. Behav Phannacol 1998; 9:345–355 © 1998 Lippincott-Raven Publishers.