BACKGROUND: In 2012, Ottawa Public Health (OPH) partnered with the City of Ottawa Municipal Child Care (MCC) Services to develop Healthy Eating and Active Living (HEAL) Guidelines. SETTING: The Guidelines aim to promote consistent standards of practice in child care settings related to healthy environments and food, physical activity, physical literacy, decreased sedentary behaviours, and positive role modeling by staff. The Guidelines targeted 498 children aged 18 months to 5 years, attending MCC centres. Resources and training were provided to 10 supervisors, 63 child care educators and 9 cooks. INTERVENTION: Components of the Guidelines were piloted in 5 MCC sites prior to being launched in 10 MCC sites across Ottawa, Ontario. Two project Advisory Groups supported the development of the Guidelines. Staff training, resources, recipes and menus were provided. An evaluation was conducted and has informed the Guidelines' subsequent community implementation. In 2015, accompanying web-based resources and e-modules were developed. OUTCOMES: The evaluation demonstrated environmental and programming changes. Parent satisfaction was high and preliminary findings showed no real changes in food costs. Following implementation, the cooks reported high compliance to the 6-week menu plans provided, and the number of sites offering 120 minutes or more of daily physical activity increased. IMPLICATIONS: Through novel intersectoral partnerships, OPH was able to implement and evaluate HEAL Guidelines in tandem. The interdisciplinary project Advisory Groups, training of cooks, and engagement of the Ontario Coaches Association were all innovative elements of this project and may influence future public health activity in this area. (author abstract)