Referral letters and replies are an important vehicle for conveying information about patients and for creating and sustaining professional relationships. Studies of communication between hospital specialists and GPs, however, suggest that improvements could be made to the content of letters. In this study, which is part of a larger study of referral expectations, a sample of 39 letters to and from the ENT and Rheumatology departments at Sunderland Royal Infirmary was analysed to find out what objectives were being achieved through the correspondence between consultants and GPs. An analytical framework of letter content was derived from a review of 25 letters to and from each specialty and from a separate study of doctors' opinions of letter content conducted by two of the authors. Doctors recruited to the present study were involved in devising a weighted scoring system for letter content. Analysis showed that the letters accomplish the basic objective of transferring clinical and administrative information. They were less likely to contain items of a socio-psychological type. There was very little difference in the standardized letter scores between the two specialties. While the level of detail recorded in this sample may be adequate for straightforward referrals, there are indications that clinicians' letters are frequently not addressing nonclinical matters that can be a complicating factor in a proportion (perhaps a fifth) of referrals. This may be a possible topic for audit in multidisciplinary groups.