The inclusion of single-case design (SCD) studies in meta-analytic research is an important consideration in identifying effective evidence-based practices. Various SCD effect sizes have been previously suggested; non-overlap of all pairs (NAP) is a recently introduced effect size. Preliminary field tests investigating the adequacy of NAP are promising, but no analyses have been conducted using only multiple baseline designs (MBDs). This preliminary study investigated typical values of NAP in MBDs, investigated agreement with visual analysis, and suggested cut scores for interpreting a NAP effect size. Typical values of NAP in MBDs were larger compared to a previous meta-analysis of studies using AB, MBD, or ABAB withdrawal designs, and agreement of suggested cut scores and visual analysis was moderate.