A study was conducted to examine the feasibility, problems, benefits, and implications of the use of the mastery learning strategy in secondary marketing programs implementing the MarkED Model Program. The MarkED Model Program, begun in 1982, is a professional development activity for secondary marketing educators that uses a competency-based, mastery learning approach to instruction. The participants (now 50 in number from across the United States) are given initial and follow-up training over a period of 3 years to prepare them to implement the mastery learning approach. Participants also work to develop their local curricula to ensure consistency with the National Curriculum Framework. The mastery learning instructional strategy assumes that most students can successfully master the course objectives given varying amounts of time and instructional resources. Two sites of the MarkEd program were studied, one in the first year of implementation and one in the third year of implementation. Interviews with students, former students, teachers, administrators, and MarkED staff were conducted, along with literature review and observations over a period of 6 months. Two case studies were constructed along with a cross-case analysis. Data were analyzed primarily by using a pattern-matching technique with patterns from the emerging data compared to patterns from the literature and a pilot study. The information gained from the study is a detailed picture of the actual practice of the use of the mastery learning strategy in marketing education classrooms participating in the MarkED Model Program. The study found that although there are a few problems associated in implementing the strategy, the mastery learning strategy and the concepts of the MarkED Model Program provide opportunities for most students to achieve at mastery levels. (The cross-case analysis is included in this report. There are 13 references.) (Author/KC)