The association between social anxiety disorder (SAD) and attention-deficit/hyperactivity disorder (ADHD) is poorly established. In fact, increasing and converging evidences suggest that there is a close relationship between the two disorders. High comorbidity rate between these two disorders, follow-up studies showing high rates of later development of SAD in ADHD and treatment studies in which ADHD medications have been helpful for both conditions all indicate this relationship. Recently, we have published a hypothesis regarding the development of SAD secondary to ADHD. In this hypothesis, we recognized that patients with SAD seem to go through a prodromal period that we labeled as "pre-social anxiety." Detecting patients in this period before meeting full-blown SAD criteria provides early intervention and prevention of SAD. New, comprehensive follow-up studies which will investigate whether ADHD causes later SAD secondarily are needed. In the current review, taken into account our developmental hypothesis, we will discuss whether high comorbidity of SAD and ADHD is a chance finding (i.e., the two disorders are found in cases with no causal relationship between them) or can SAD develop secondarily due to childhood ADHD. Is there a prodrom period in patients with SAD as in cancer or psychosis patients? We are going to summarize the overlapping features of SAD and ADHD in terms of child/parents interaction and family issues, aversive childhood experiences, social skill deficits, and development of cognitive distortions.