Background and objectives: Repetitive thought is a trans-diagnostic risk-factor for development of psychopathology. Research on repetitive thought in bereaved individuals has focused primarily on clarifying the role of rumination, repetitive thinking about past negative events and/or negative emotions. While detrimental effects of rumination have been demonstrated following bereavement, surprisingly few studies have aimed to clarify the role of worry, repetitive thinking about potential future negative events, in adjustment to loss. This study sought to fill this gap in knowledge. Methods/Design: One hundred eighty-three bereaved individuals (85.3% women) filled out questionnaires on sociodemographic and loss-related characteristics, worry, and symptom measures of depression, anxiety, and prolonged grief. After six months, 155 participants completed worry and symptom measures again. Using multiple regression analyses, concurrent and longitudinal associations between loss-related variables, worry, and symptoms of psychopathology were examined. Results: Main results were that worry was strongly positively associated with symptoms of anxiety, depression and prolonged grief concurrently and also predicted higher levels of anxiety, depression and prolonged grief longitudinally. Conclusions: Findings suggest that worry influences adjustment to bereavement negatively and may be a potential target in grief therapy, especially when aiming to reduce anxiety.