Using information on clinical risk factors provided through the medical record linkage system of the Rochester Epidemiology Project, we conducted a population-based case-control study of Alzheimer's disease (AD). During the period 1960 to 1974, we identified 415 newly diagnosed cases of AD among residents of Rochester, Minnesota, and matched one community control to each case based on age, sex, and duration of community medical record. We estimated odds ratios using conditional logistic regression for several potential clinical risk factors of AD. Among more than 20 clinical risk factors that were evaluated, the only statistically significant findings were for episodic depression, personality disorder, and hypertension.