It is estimated that over 800,000 men and women become bereaved each year in the United States (LaRue et al, 1985). While the near certainty of such bereavement is predictable in one spouse or the other, the exact impact and duration of bereavement is much less predictable (Stroebe et al, 1995). It has been reported that the loss of a spouse is rated as the major life stressor among survivors of varying ages and diverse cultural backgrounds (Holmes and Rahe, 1967). As one copes with the loss of a loved one, expected reactions include sadness, tearfulness, and even depression (DeLeon, 1994; Pasternak, 1996). Other complications can include work-related difficulties, sleep disturbances, irrational behaviors, and immunologic dysfunction (Zisook, 1994; Prigerson, et al, 1995). All of these symptoms are common; yet, the underlying biology and relationship with the time course of bereavement are still poorly understood. The purpose of this study will be to prospectively follow a cohort of elderly bereaved spouses and controls from multiple clinical and biological perspectives over thirteen months after the loss of a spouse.