Chronic intravenous drug self-administration in rodents is a useful procedure for predicting the abuse liability of novel drugs in humans, for evaluating candidate treatments for drug abuse and dependence, and for studying the biological basis of addiction. This unit focuses on recent technical innovations for conducting long-term studies of i.v. drug self-administration behavior in healthy, freely moving rats and mice. Included are protocols for construction, implantation, and maintenance of chronic indwelling jugular catheters, commentary on critical parameters, a troubleshooting guide, and anticipated results.