Purpose: This case study is presented to inform the reader of potential speech, language, cognitive, and emotional characteristics in preadolescent cluttering. Method: This case study describes a 10-year-old boy who started to clutter during preadolescence. The case illustrates that, in some adolescents, cluttering can co-occur with temporary stuttering-like behavior. In this case, signs of disturbances in speech-language production associated with behavioral impulsiveness as a young child were noted. Speech, language, cognitive, and emotional results of the case are reported in detail. Results: The changes in fluency development are reported and discussed within the context of changes in the adolescent brain as well as adolescent cognitive and emotional development. While being unaware of their speech condition before adolescence, during preadolescence, the changes in brain organization lead to an increase in rate and a decrease in speech control. Given that the client had limited understanding of what was occurring, they were at risk of developing negative communication attitudes. Speech-language therapists are strongly advised to monitor children with cluttering signals in the early years of their adolescence.