This paper will discuss some of the considerations that a manufacturer of strongly branded food products takes into account when facing the opportunities and problems of extending the range of varieties presented by a single brand. It offers no grand theory or solutions, but illustrates, with sane examples, pragmatic approaches to specific cases, with emphasis on the market research involvement. Examples will be discussed, principally of research into the extension of a leading brand in the pet food market by the addition of varieties, and also of confectionery brands by the addition of product and packaging variations. The research is primarily concerned, particularly in the early stages, with the consumer. It is aimed at discovering likely consumer acceptance. Certainly later research is very much concerned with monitoring the performance of line extensions in terms of sales and distribution in the various sectors of the retail trade, and conducting associated analyses of the extent of trade stocking of combinations of the range varieties.