Objective Obesity related health problems affect individuals, families, communities and the broader health care system, however few healthcare providers (e.g., doctors, nurses, social workers, psychologists, counselors) receive formal training in obesity prevention interventions. We examined the effectiveness of training healthcare providers in brief motivational interviewing (brief MI) targeting eating and exercise behavior change. Methods 163 healthcare providers participated. 128 participants completed a one-day experiential brief MI training workshop followed by electronic peer-support and a further 35 matched controls did not receive the training. Results Participant's knowledge of brief MI and confidence in their ability to counsel patients using brief MI significantly improved following training (p < 0.05) and remained at 3 and 6-month follow-up (p < 0.05). Brief MI skills assessed during the simulated patient interactions indicated a significant improvement across two practical training blocks (p < 0.05). Conclusion Healthcare providers can learn brief MI skills and knowledge quickly and confidence in their counseling abilities improves and is sustained. Practice implications Healthcare providers may consider brief MI as an obesity prevention intervention.