Counselor competence in telephone Motivation Interviewing (MI) to change lifestyle behaviors in a primary care population was assessed using the Motivational Interviewing Treatment Integrity (MITI) rating system. Counselor behavior was evaluated by trained raters. Twenty minutes of a random sample of 336 MI sessions were coded representing 232 counselees. Ninety-four sessions (28%) were double coded to assess inter-rater agreement. The MI fidelity was examined by comparing the MI fidelity scores direction, empathy, spirit, % open questions, % complex reflections, reflections-to-questions ratio, % MI-adherent responses with the matching beginner proficiency MITI threshold. The inter-rater agreements for the MI fidelity summary scores were good (spirit, reflections-to-questions ratio), fair (empathy, % open questions, % MI-adherent responses) or poor (direction, % complex reflection). The MI fidelity scores for direction, empathy, spirit and the percentage of complex reflections exceeded the MITI threshold, but lower scores were found for the percentage of open questions, the reflections-to-questions ratio and the percentage of MI-adherent responses. In conclusion, evidence that MI was implemented was revealed. However, the inter-rater agreements scores and some fidelity scores leave room for improvement indicating that raters and counselors may need more ongoing training and feedback to achieve and maintain adequate competence. These findings apply to more complex skills (as rating complex reflections) in particular.