Fears and apprehensions are often cited as contributing to decreased quality of life; however, questions relating to worry over the future are rarely included in generic quality-of-life questionnaires. We report an effort to quantify the effect of fear on quality-of-life domains as measured by using the Short-Form 36 (SF-36) Health Survey. In the course of developing an osteoporosis-targeted quality-of-life (OPTQoL) questionnaire, we asked participants to complete the SF-36 Health Survey and another questionnaire containing items that women with osteoporosis could be expected to find difficult or worrisome. Two hundred twenty-two women with established osteoporosis (loss of height, kyphosis, history of fractures); 101 women with known low bone mineral density (BMD) but without established osteoporosis; and 142 women with no known osteoporosis completed both the osteoporosis questionnaire and the SF-36 Health Survey. This test version of the OPTQoL contained two domains for fears of osteoporosis and the consequent fractures and deformities; these domains were termed fears now and fears future. After adjusting for age and selected comorbidities, we estimated the additional contribution of the two fears domains on the domain scores of the SF-36 Health Survey. For women with established osteoporosis, the fears now domain explained 4% to 8% of the variance within each domain of the survey. For women with low BMD only, fears now had a significant effect only on the physical functioning domain of the survey and explained 4% of the variance of that domain. Fears future had a significant role in explaining the SF-36 Health Survey score on all domains except physical functioning among women with established osteoporosis; however, the fears future domain explained less of the variance (2% to 5%) among these women than did the fears now domain. For women with low BMD only, fears future had a significant impact only on the mental health and the general health domains (4% and 5% of the variance, respectively). Osteoporosis-related fears appear to explain a small but significant percentage of the variation in quality of life for women in midlife.