Community-based participatory research (CBPR) is an emerging research approach with the aim of increasing sampling of diverse populations in studies. The purpose of this study was to evaluate the psychometric properties of scores on the CBPR Knowledge Self-Assessment Scale (CBPR-KSAS) using Rasch analysis. The scale was completed by 204 participants. The data fit the Rasch model well, were sufficiently reliable and unidimensional, and separated the respondents into four statistically distinguishable groups. The item hierarchy was partially supported theoretically by distinguishing the lower, middle, and upper ends of CBPR knowledge competencies. These results provide empirical support that CBPR knowledge can be conceptualized and measured on a meaningful continuum.