The effects of systemic (0–1.0 mg/kg) or intraaccumbens (0–1.0 μg/side) administration of SCH‐23390 on cocaine‐induced (0 or 4.2 mg/kg, IV) locomotion, sniffing, and conditioned place preference (CPP) were investigated in rats. After behavioral testing was completed, animals were injected with their respective dose of SCH‐23390 into the nucleus accumbens (NAc), followed by a systemic injection of the irreversible antagonist N‐ethoxycarbonyl‐2‐ethoxy‐1,2‐dihydroquinoline (EEDQ). Receptors occupied by intraaccumbens SCH‐23390, and therefore protected from EEDQ‐induced inactivation, were then quantified from autoradiograms of sections labeled with ³H‐SCH‐23390. Systemic administration of 0.5 and 1.0 mg/kg SCH‐23390 reversed cocaine‐induced locomotion, sniffing, and CPP, suggesting that stimulation of D1‐like receptors is necessary for these behavioral changes. Intraaccumbens administration of 1.0 μg/side SCH‐23390 reversed cocaine‐CPP, and this dose occupied D1‐like receptors primarily in the rostral pole of the NAc. Intraaccumbens administration of 0.5 μg/side SCH‐23390 reversed cocaine‐induced locomotion. However, this dose occupied a similar number of D1‐like receptors in the NAc as a lower and behaviorally ineffective dose of 0.1 μg/side, but occupied more receptors in the caudate‐putamen relative to both the 0.1 and 1.0 μg/side doses. These findings suggest that stimulation of D1‐like receptors in the NAc is necessary for cocaine‐CPP, but not for cocaine‐induced locomotion. Synapse 30:181–193, 1998. © 1998 Wiley‐Liss, Inc.