Losses are an integral part of chronic illness and disability. The term chronic sorrow, has been used to describe the long-term periodic sadness the chronically ill and their caregivers experience in reaction to continual losses. In this conceptual analysis of chronic sorrow, identified critical attributes are: cyclic sadness over time in a situation with no predictable end; external and internal stimuli triggering the feelings of loss, disappointment, and fear; and, progression and intensification of the sadness or sorrow years after the initial disappointment or loss. Model, borderline, related, contrary, and illegitimate cases illustrate what the concept is and what it is not. The meaning of chronic sorrow is compared to the meaning of unresolvable grief and depression. Chronic sorrow in various stages of life is illustrated in descriptions of: the situation and feelings of parents of handicapped children; multiple sclerosis patients in the middle, productive years; and elderly caregivers of spouses with dementia. Implications for research include the need to study the concept in various populations to determine its prevalence and operation. Through research, the meaning of the concept can be further clarified. This is a beginning step toward developing nursing theory that will give direction for providing care to persons encountering sadness over long periods of time.