Cyanamide or disulfiram serves to suppress volitional intake of alcohol presumably because of the toxic build-up of acetaldehyde dehydrogenase (AIDH). However, the presence of acetaldehyde systemically favors the in vivo synthesis of addictive-like metabolites in the brain which in turn enhance alcohol drinking. The purpose of this investigation, therefore, was to determine whether cyanamide administered to the rat, which did not have access to alcohol during treatment, would nevertheless affect the subsequent preference for alcohol. In the first experiment, cannulae were implanted bilaterally above the cerebral ventricle of 33 adult male Sprague-Dawley rats so that an artificial CSF or a solution of cyanamide could be infused intracerebroventricularly (ICV). Following post-operative recovery, each rat was tested for its alcohol preference by offering it water and a solution of ethyl alcohol which was increased over 8 days from 3–20%. After a single test concentration of alcohol (range of 5–9%) was selected for each individual animal presented with water over a 5-day interval, cyanamide was infused in a volume of 2.5 μl per side three times daily for 4 days in one of the following total doses: 0.03, 0.1, 0.3, 0.5 or 1.0 mg. A second five-day preference test was run, and 6 weeks following cyanamide infusions a final 3–20% alcohol preference screen was run over 8 days. The results showed that a long-term, dose-dependent increase or decrease in alcohol intake occurred in those rats reactive to the drug. Given ICV, the 0.3 mg dose of cyanamide was the most efficacious in significantly augmenting alcohol consumption, whereas the two lower doses also enhanced alcohol intake but in fewer animals. Although the highest ICV dose of 1.0 mg cyanamide consistently suppressed alcohol intake, a dose of 0.5 mg produced mixed effects on the self-selection of alcohol. In the second experiment, either a saline control or cyanamide solution was injected subcutaneously in a dose of 10.0 and 15.0 mg/kg in a group of 11 rats twice a day for three days following an 8-day, 3–30% alcohol preference screen. To test the time course of action of cyanamide on alcohol drinking, a second alcohol preference test was conducted after the injection sequence which was then followed by a third test 6 weeks after the treatment. Cyanamide in both doses augmented alcohol intake which, when tested 6 weeks after cyanamide treatment, persisted in a manner similar to that observed in rats given the drug by the ICV route. Taken together, these findings suggest that an increase in the level of one or more biogenic aldehydes produced endogenously by repeated injections of cyanamide, both in brain and in the periphery, can induce a prolonged enhancement of alcohol drinking