The Solid Waste Management Act of the Philippines was passed in Congress in light of the mounting garbage problem that has compromised public health and the environment. In line with this, Cagayan de Oro City put into implementation City Ordinance No. 8975-2003 or Mandatory Segregation of Waste at Source. The study determined following: (1) the level of knowledge of urban barangay leaders regarding City Ordnance Number 8975, in terms of: nature and purpose and features of the City Ordinance 8975; (2) the level of compliance of urban barangay leaders toward City Ordinance No. 8975; (3) the most prevalent reason that encourages compliance of the ordinance; (4) the most prevalent reason that discourages compliance of the ordinance; and (5) the significant relationship between level of knowledge and prevalent reason that encourages and discourages compliance of City Ordinance 8975. On the average, the urban barangay chairmen had technical background of the Ordinance in terms of its nature and features. It was also apparent that the major reason for compliance was personal knowledge while non compliance was institutional illegitimacy and ineffectiveness. Further analysis also demonstrated that a significant relationship exists between level of knowledge of City Ordinance 8975 and the primary reason for compliance and non compliance to the mandate of the mentioned ordinance.