This study adopted a systemic-functional approach to analyse the language issues that examiners referred to in their reports on candidates' performance in mathematics and science examinations administered by the Caribbean Examinations Council (CXC) in 2010-2011. Content analysis of reports in mathematics, chemistry, biology, physics, human and social biology, and integrated science identified four salient areas of language challenges for students - subject discipline terminology, data representation, content area reading, and content area writing - as these related to students' understanding and expression. Examiners' recommendations to address these issues were also analysed. It is suggested that Caribbean students may be facing challenges in accessing academic language through a language that is not their first language, and that this influences their ability to use conventional tools of the disciplines to show their understanding of mathematics and science in examinations. The article also makes recommendations for curricular review to provide greater opportunities for students to develop critical language skills in content areas.