This paper is concerned with the development or theory in the discipline of nursing as it is practised in Great Britain It stems from dissatisfaction with the generally uncritical adoption by British nurses of models of nursing which have been developed to explain and enhance North American practice After the introductory paragraph, four roles for nursing theory are proposed These are to define nursing by describing nursing phenomena, to form a realistic basis for curriculum design, to provide tools for the professional prachce of nursing, and to provide a nursing language It is then argued that although British nurses have recognized the need for an adequate theoretical basis for practice, their response has been rather uncritical adoption of American models of nursing As a basis for practice, it is argued that American models generally fail to meet the needs described above, and therefore fail to have impact on clinical work Structural and philosophical reasons for this failure are identified Following a brief discussion of the inductive and deductive approaches to the development of theory, the paper closes with the argument that British nurses should be concerned with the development of new theory which, if grounded in the reality of practice, would be likely to be both useful and realistic