Specific phobias (also referred to as simple phobias and isolated phobias) represent a heterogeneous group of disorders characterized by excessive and/or irrational fear of one of relatively few and usually related objects, situations, places, phenomena, or activities (phobic stimuli). The phobic stimuli are either avoided or endured with intense anxiety or discomfort. People with specific phobias are aware that their fear is unreasonable, but this does not diminish the intensity of the fear. Rather, they are quite distressed about being afraid or feel handicapped by their phobia. Specific phobias are frequently encountered in the general population, but they are relatively uncommon in the clinical setting. Most phobias have a remarkable tendency to persist, prompting an assumption that they cannot be easily extinguished because of their ‘‘purpose’’ to protect against danger. Specific phobias are deceptively simple, as they are easy to describe and recognize but often difficult to understand. There are several conceptual problems and a number of issues associated with specific phobias:… 1. Where are the boundaries of specific phobias? How can we develop better criteria on the basis of which specific phobia could be distinguished as a psychiatric disorder from fears and avoidance considered to be within the realm of ‘‘normality?’’ 2. How can specific phobias be taken seriously by both the sufferers and clinicians? 3. In view of the considerable differences between various types of specific phobias, should they continue to be grouped together? 4. Should specific phobias be grouped on the basis of whether they are driven by fear or disgust? 5. In view of its unique features, should the blood-injection-injury type of specific phobia be given a separate psychopathological, diagnostic, and nosological status? 6. Considering a significant overlap between situational phobias and agoraphobia, should they be grouped together, along a hypothetical situational phobia/agoraphobia spectrum? 7. What is the relationship between specific phobias and other psychopathology? Are they relatively isolated from other disorders, both cross-sectionally and longitudinally, or should they more appropriately be conceptualized as a predisposition to or a risk factor for some psychiatric conditions? 8. How specific are pathways that lead to specific phobias? 9. Has the dominant treatment model for specific phobias, based on exposure therapy, exhausted its potential? Is the tendency for specific phobias to persist adequately addressed by treatments derived from learning theory?