Formal humor training for therapists is proposed as an elective part of their academic curriculum. The paucity of rigorous empirical research on the effectiveness of this historically controversial form of clinical intervention is exceeded only by the absence of any training for those practitioners interested in applying humor techniques. A representative sample of its many advocates' recommendations to incorporate humor in the practice of psychological therapies is reviewed. Therapeutic humor is defined, the role of therapists' personal qualities is discussed, and possible reasons for the profession's past resistance to promoting humor in therapy are described. Research perspectives for the evaluation of humor training are presented with illustrative examples of important empirical questions. In addition to its potential salubrious effects on clients, therapeutic humor might have the positive side effect of preventing or minimizing professional burnout in therapists. This potentially major psychotherapeutic resource, highly praised by some, remains insufficiently evaluated and essentially untapped.