Clinical Question: For individuals who stutter (P), which behavioral treatment approaches (I, C) are most effective in promoting fluent speech (O)? Method: Systematic Review and Meta-Analysis. Study Sources: CINAHL, CINAHL Plus (with Full Text), ERIC, MEDLINE, PsycINFO, and ProQuest Dissertations & Theses Full Text. The authors also conducted an ancestry search from all studies meeting the inclusion criteria previously described. Search Terms: stutt* OR stamm* AND treat* OR interven* OR therap* AND single subject OR multiple baseline. Number of Included Studies: 19. Primary Results: A total of 19 studies representing 74 participants met the inclusion criteria and yielded an average mean baseline reduction (MBLR) of stuttering behavior by 67%. An overall improvement of nonstuttered speech behavior represented by the percentage of non-overlapping data points (PND) resulted in a 49% improvement representing 19 participants. Analyses suggest that a fluency shaping program or assertiveness training program, in one form or another lead to fluency improvement. The question remains if participant characteristics (i.e., age, stuttering severity, level of social anxiety, using coping behaviors, presence of negative speech-associated cognition, among others), are variables to account for when considering a treatment approach. Conclusions: These data are consistent with previous meta-analysis and systematic review stuttering intervention group results indicating that, for the vast majority of the participants, treatment has a positive effect on their speech and support for a range of treatment procedures exists. Further research is needed to determine which participant characteristics are important to consider when determining the best treatment approach for an individual.