The purpose of this study was to examine patterns and factors influencing exclusion rates and achievement on large-scale assessments in Canada. Data analysis employed a case study to examine policies and practices of exclusion, absenteeism, and social promotion related to large-scale assessments at the international, national, and provincial levels. In addition, information was solicited from assessment experts regarding exclusion rate practices. Findings revealed significant increases in student performance, which paralleled significant increases in exclusion rates. At the provincial level, the analysis led to the discovery of the relationship between social promotion policies and a document guiding assessment practices in Canada (i.e., Principles of Fair Assessment Practices). This relationship was the rationale given for excluding poor performing students, not learning or physically disabled students, from participating in large-scale assessments. Recommendations include an alignment of exclusion policies between the three levels of administration, documenting students who are unable to participate on large-scale assessment because they are operating too far below grade level as a result of being social promoted, and to over sample provinces and schools with high absenteeism on assessment days.