Self-administration of the high-affinity cocaine analog 2 beta-carbomethoxy-3 beta-(4-fluorophenyl)tropane (CFT) and cocaine were compared in squirrel monkeys responding under a second-order schedule of IV drug injection. Both CFT and cocaine maintained self-administration in all subjects. As the dose of either drug was increased, the rate of responding first increased and then decreased. Although the two drugs had qualitatively similar effects, CFT was approximately six times more potent than cocaine. This potency relation corresponds closely with the potency relations reported for CFT and cocaine in studies of dopamine uptake inhibition and binding at cocaine recognition sites. The results are consistent with the view that the reinforcing effects of cocaine-like drugs are mediated at cocaine recognition sites associated with the dopamine uptake system, and suggest that radioligand probes based on CFT may be suitable markers for these sites.