Abstract
In treating a sexual problem which exists in a relationship, the non-sexual interaction between the two people involved cannot be ignored. From Masters & Johnson onwards, sex therapists have treated the couple as the unit of therapy, unless there is no relationship to be treated. This review looks at the various dysfunctions and sexual motivational problems, their causation, the contribution of relationship factors, principles of couple therapy using the behavioural systems model and finally the specific management of some problems using couple therapy as well as sex therapy.