Primary care in the United Kingdom has been advocated as an optimal location for the provision of genetic services for common diseases. Little, however, is known about general practitioners' own views toward this suggestion or the possible demand for such services from patients. To assess general practitioners' attitudes to providing genetic services for common diseases, and to estimate the demand from patients for these services, we used a single-page postal questionnaire survey of all 359 general practitioners registered with the Oxfordshire Health Authority; 339 (94%) responded. These physicians reported that a mean 4.1 patients (95% CI, 3.3-4.9) out of every 1,000 consulting them were concerned about their own risk of a common disease associated with a diagnosis in a family member. Half of the general practitioners (95% CI, 45-56%) counseled about genetics in the last year. A majority of general practitioners accept the need to provide genetic services, but far fewer are competent to do so. Although 60% (95% CI, 55-65%) believed they should be involved with genetic screening for common diseases, only 29% (95% CI, 24-34%) felt sufficiently prepared to take family histories and draw pedigrees, and only 15% (95% CI, 11-19%) felt sufficiently prepared to counsel patients about their genetic test results. Given the necessary training and information, 63% (95% CI, 58-68%) and 64% (95% CI, 59-69%) were willing to provide these services. Even with training and information, not all would be willing to provide these services, and lack of time may be a major deterrent. "Practice-enabling" strategies, such as computerized aids in genetics, may be useful.