Purpose: This scoping review examined differences in types and/or frequency of speech disfluencies between multilingual individuals who do and do not stutter. We also examined whether language dominance and/or proficiency influences the types and frequency of speech disfluencies.

Method: The review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews guidelines. The search was conducted using inclusive search strings related to multilingualism and speech disfluencies in Medline, Web of Science, Scopus, and Embase. The following information was extracted for each of the studies: general study information (number of participants, types of study groups, age groups, language dyads), study method, types of collected speech samples, terms used for referring to disfluencies, the definition of the term "disfluency," the types of disfluencies assessed, the proposed causal mechanism of disfluencies in multilinguals, the frequency of disfluencies, and identified group differences in disfluencies. Of the 792 records screened, 68 were included in the review.

Results: Similar types of speech disfluencies were present in the speech of multilinguals who do and do not stutter. However, a clear difference was apparent in the frequency of stuttering-like disfluencies between groups; the frequency of other disfluencies had a similar range. Monolingual guidelines do not apply to multilingual speakers. Finally, most records reported a higher frequency of speech disfluencies in both groups' less dominant and/or proficient language.

Conclusions: This review provides insights on assessing stuttering in multilingual clients to avoid misdiagnosis of stuttering in this population. Research into the aspects of speech disfluencies in multilingual individuals who do and do not stutter is limited, and further research is warranted to deepen our understanding of how different aspects of multilingualism influence the manifestation of speech disfluencies in both groups. Therefore, there is a strong need for a systematic and uniform approach to define and evaluate speech disfluencies in multilinguals.