The Childhood-Onset Fluency Disorder (stuttering) reflects a marked impairment in speech fluency that is not attributable to stroke or another medical condition, and developmental or mental disorder (Birstein, 2015). This article examines Childhood-Onset Fluency Disorder (Stuttering): An interruption in the flow of speaking. The focus is on the Diagnostic Criteria in DSM-5 ["Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition"] Diagnostic Criteria, Diagnostic Features, Prevalence and Risk Factors are discussed.