Like other Jamaican secondary schools, Saint Mary's College uses a selection process to accept students starting at seventh grade.

Girls in first through third form wear a sky blue double pleated tunic over a short-sleeved gold blouse.

Boys wear khaki pants and shirts with blue and gold crest and striped epaulettes.

Sixth form boys wear long-sleeved white shirts, khaki pants and a gold tie striped with blue.

Subjects offered to students include Technical Drawing, Wood Works, Mathematics, Physical Education, General Science, Social Studies, Home Economics, Biology, Geography, History, Physics, Food and Nutrition, Clothing and Textiles, Principles of Accounting, Office Administration, Principles of Business, English, Chemistry, Information Technology, Electrical Principles, Literature, Spanish, Art and Religious Education.