OBJECTIVES: We aimed to examine the relationship between doctors' willingness to refer elderly patients for elective surgical operations and patients' age, comorbidity, institutionalization, living habits and signs of dementia. METHOD: A random selection of 837 medical doctors in Finland (response rate 56%) received a postal questionnaire consisting of 18 vignettes, i.e. imaginary patient cases. Respondents were asked whether they would refer the patient on the vignette for elective surgical operation, treat the patient conservatively, or choose some other alternative. In the vignettes, the age of patients was randomly varied between 65 and 85, at 5-year intervals, to provide eight different questionnaires, and each respondent obtained one of them. RESULTS: The proportion of doctors willing to refer the patients for surgery was inversely related to the patients' age: in all the vignettes, doctors said they would refer fewer patients in the oldest age groups. Almost all the doctors claimed they would refer healthy, home-dwelling persons aged 65-70 years for operations. In the oldest age groups of patients, the doctors' willingness to refer was highest for cataract operations (69%) and hip prosthesis operations (63%), but only 18% of doctors would refer such patients for coronary by-pass operations. Comorbidity and institutionalization were associated with fewer doctors referring the patients: the proportion of doctors willing to refer these patients was about half that of those willing to refer otherwise healthy and home-dwelling patients. Smoking by patients also decreased the proportions of doctors willing to refer, but moderate signs of dementia in an elderly patient with cataract were associated with only a slight decrease in referring. CONCLUSIONS: Doctors are less willing to refer old patients for elective surgery, but comorbidity, patients' lifestyle and institutionalization have a greater effect on referrals than age.