This thesis examines approaches to content-based language teaching ( CBLT) in the context of the teaching of English as a second language (ESL) in secondary schools. Issues relate to the nature of the second language curriculum, and the way that the cultural incorporation of ESL students may be effected by schooling. It is argued that ESL students need to be provided with some explicit attention to key elements in each of these areas of learning, if schooling is to be an empowering process, helping ESL students to develop as bilingual people in a multicultural society. The literature on content-based language teaching is surveyed. The nature of descriptive frameworks of practice in CBLT, frameworks for the implementation of CBLT, attempts to define the elements of CBLT and definitions of CBLT are explored. The nature of the practices that claim, or are described as CBLT is explored. Three representative implementational frameworks for CBLT are examined in relation to the way that they integrate language and subject matter, the extent to which they involve learners in paying attention to language, subject matter and cultural factors relevant to schooling. Problems involved in current approaches to CBLT that relate to the need for reference to a broader language curriculum are identified and the potential that CBLT has in identifying the language and other learning needs, and of providing integrated instruction for ESL students in secondary schooling is discussed.