PURPOSE: to investigate and compare the risk factors for stuttering between children with familial developmental stuttering and children with sporadic developmental stuttering. METHODS: 60 children of both genders with stuttering took part, divided in two groups: GI - 30 children with familial developmental stuttering; GII - 30 children with sporadic developmental stuttering. Data were gathered through the Protocol of Risk for the Developmental Stuttering - PRGD (Andrade, 2006), which considers the following factors: age; gender; manner of onset and time of duration for the disfluencies; typology of the disfluencies; associated communicative and qualitative factors; physical and emotional stress; family history concerning stuttering; personal, familiar and social reaction, and familiar attitudes. RESULTS: when Group I (GI) was compared to Group II (GII), the only statically difference was related to emotional stress that occurred near the onset of the disorder. CONCLUSION: the results confirm the complexity of stuttering, as well as the need for investigating the risk factors for this disorder in order to improve the understanding of its possible etiologies.