Exploitation in therapy and counselling may occur in only a minority of cases, but when it does, its effects are potentially damaging to both the client and the profession. Exploitation in therapy may take the form of psychological, covert and overt abuse. The most reported form of abuse of the therapeutic relationship is of a sexual nature. However, psychological abuse usually forms the backdrop to sexual exploitation, preceding and perpetuating the sexual involvement. Sexual exploitation in therapy is an abuse of the power imbued in the therapist by nature of his professional role. It allows the therapist a sexual gratification which he would not have been likely to achieve outside the therapeutic relationship. The prevention of sexual exploitation in therapy is an issue of concern to training, employing and professional organisations who seek to maintain high standards of counselling delivery. Determining the variables which may contribute to exploitation is fundamental to avoiding its incidence. This paper discusses the factors underlying the use of therapy and counselling as a medium for therapist abuse. It examines (i) the prevailing conditions for abuse to occur, (ii) how the therapist overcomes client resistance, and (iii) the implications for the maintenance of professional standards.