Adolescence is a transitional period during development that is associated with a greater likelihood of addiction to drugs than any other age. In the prefrontal cortex (PFC), D₁dopamine receptors mediate motivational salience attribution, which plays a role in addiction. Here, we investigated the relationship of age-related D₁dopamine receptor expression in the PFC with the maturation of cocaine place conditioning. Confocal microscopy revealed that retrogradely traced cortical output neurons to the nucleus accumbens express higher levels of D₁receptors during adolescence compared with younger and older ages. D₁expression does not change on GABAergic interneurons across age. Adolescent differences in D₁expression occur independently of cortical-accumbens connectivity, which proliferates through adulthood. Behaviorally, adolescent rats are more sensitive to cocaine place conditioning than younger and older rats. However, microinjections of the D₁antagonist SCH23390 into the PFC blocked adolescent place preferences, whereas microinjections of D₁agonists dose-dependently increased preferences for cocaine-associated environments previously not preferred by juveniles. These results suggest that the heightened expression of D₁receptors on cortical-accumbens projections may help explain increased sensitivity to environmental events and addictive behaviors during adolescence, whereas the paucity of D₁-expressing projections may reduce risk in juveniles.