This is a "state of the issue" paper about gender and physical health. It organizes the hypotheses proposed for male-female differences in physical health status, therapeutic health behaviors, and longevity and its summaries empirical research, especially sociological research, on the topic over the past 10-15 years. Capsule summaries of sex differentials in health and of recent trends in health and morality are also presented for American (U.S.) men and women. The central theoretical viewpoint of this paper is that sex differences in health are principally the outcome of differential risks acquired from roles, stress, life styles, and preventive health practices. Psychosocial factors-how men and women perceive and evaluate symptoms, and their readiness and ability to take therapeutic actions-are important as well, but typically secondary to acquired risks. Other factors such as prior health care, biological risks, health reporting, and caretaker effects (for example, physician sex bias) have even smaller importance. We hypothesize that the relative weight of acquired risks and psychosocial factors varies for different types of health problems as follows: (1) Psychosocial factors have their greatest weight in responses to chronic, nonfatal, or low severity diseases and injuries and (2) gender differences are also greatest in responses to these; that is, men and women differ more in their perception, evaluation, and treatment of prolonged, mild conditions than of acute, life-threatening, or severe ones. The paper suggests some strategies for social science research on male-female health differences in the next decade or two.