Initially, the Class X final examination followed the ICSE (Indian Council of School Education) Board which continued till the year 1977. In 1978 the school also included another Board, the MBOSE (Meghalaya Board of School Education) which conducted the HSLC examination. At that time students could opt for a Board that suited their academic capabilities. In 1987, the ICSE was discontinued and replaced by the Government of Meghalaya Matric Board (HSLC) which continued till 2001-2002. Loreto Convent, Shillong was re-affiliated to the ICSE Board and the first batch appeared for the examination in 2003. The school follows the same Board till date. In 2014 affiliation was granted for the Higher Secondary Section, ISC (Humanities) by the Delhi Board. In 2016 affiliation for the ISC Science Stream was granted.
The medium of instruction of this Institution is English. Khasi and Hindi are taught as 2nd language from Class I-X. The third Language is compulsory from Class V-VIII inclusively.
The pupils are prepared for the ICSE and ISC Examination (Indian Council for Secondary Examination), New Delhi.
In addition to the subjects selected from those prescribed in the Board and Council Syllabus, the Curriculum includes Religious Instruction (for Catholics) and Value Education (for non-Catholics) as compulsory subjects. Personal and CommunityPrayer is facilitated through Assemblies, Prayer Groups, Liturgies and School Retreats.