Functional analysis methods allow clinicians to determine the variable(s) that maintain destructive behavior. Previous reviews of functional analysis outcomes have included large samples of published and unpublished data sets (i.e., clinical samples). The purpose of this review was to conduct a large retrospective consecutive controlled case series of clinical functional analyses. We sought to identify the prevalence of differentiation, procedural modifications for undifferentiated and differentiated cases, and identified function(s) of destructive behavior. In addition, we extended the existing literature by determining whether functional analysis differentiation and function varied when single or multiple behavior topographies were consequated in the functional analysis. We discuss our findings considering previously published functional analysis reviews, provide avenues for future research, and offer suggestions for clinical practice.