One of the most common challenges faced by health professionals is encouraging patients to change their behavior to improve their health. This paper reports the development of a checklist, the behavior change counseling index (BECCI). This aims to measure practitioner competence in behavior change counseling (BCC), an adaptation of motivational interviewing suitable for brief consultations in healthcare settings. The checklist has demonstrated acceptable levels of validity, reliability and responsiveness, and aims to assist trainers and researchers in assessing change in practitioner behavior before, during and after training in BCC. BECCI will also provide valuable information about the standard of BCC that practitioners were trained to deliver in studies of BCC as an intervention.