Many examples of cooperative projects between English for Specific Purposes (ESP) units and university subject departments have been reported in the literature. Most are case studies of specific ESP programs, and explanations of methodologies have not been prominent. This paper reviews the different ways in which cooperative methods have been used in ESP programs, beginning with the history of cooperative teaching methods in engineering more than 100 years ago. Cooperative methods are categorized into four types according to the level of involvement of the subject specialist in the ESP program. Advantages and disadvantages of the methods are discussed and it is concluded that the advantages considerably outweigh the disadvantages. It is suggested that the purposes of the methods are to achieve cultural syntonicity (i.e., coherence) with the content subjects, since academic development and language development proceed concurrently. The paper concludes by suggesting that ESP professionals can learn from the experience of engineering in exploiting the advantages it gained from cooperative teaching methods to improve its status. Contains 56 references. (LB)