In 2012, Massachusetts implemented a state law to establish nutrition standards for competitive foods and beverages sold or provided in public schools, similar to the federal Smart Snacks in School standards. This mixed-methods study aimed to understand food service directors’ (FSD) perspectives and experiences implementing the Massachusetts standards. The study used direct observation of foods and beverages in schools to assess compliance with the Massachusetts standards. Semi-structured interviews with school FSD conducted in 2013 and 2014 were analyzed for major implementation themes, of which some were explored in relation to compliance. Seven major themes were raise by more than two-thirds of participating school districts: 1) taking measures for successful transition; 2) communicating with vendors/manufacturers; 3) using tools to identify compliant foods and beverages; 4) receiving support from leadership; 5) grappling with issues not covered by the law; 6) anticipating changes in sales of competitive foods and beverages; and 7) anticipating changes in sales of school meals. Each theme was mentioned by the majority of more-compliant school districts (65-81%), with themes being raised more frequently after the second year of implementation (range increase 4-14%). FSD in more-compliant districts were more likely to talk about themes than those in less-compliant districts.