An easy application of counter-conditioning is aversive conditioning, where an unconditioned stimulus (also called a US) causes a noxious response (also called a UR) which is continually coupled with a negative behavior. After this frequent coupling, a conditioned response of avoidance or aversion occurs only with the CS. Besides alcohol, however, aversion therapies are effective in treating many negative behaviors, such as sexual deviancy, cigarette smoking, overeating, and Enuresis.

Treating alcoholism is also extremely effective with the use of aversive counter-conditioning, where alcohol and the drug Antabuse will be employed to produce nausea in the client. Pretty soon, even after the removal of Antabuse, the client will continue to feel nauseated when drinking alcohol. The only drawbacks to aversion therapies are that the probability that the client will relapse is very high, there are ethical issues involved, and there are technical problems.