Worry has been identified as a key factor in psychopathology after acquired brain injury (ABI). Network analysis studies have shown that worry is highly interconnected with other psychiatric symptoms and post-stroke complications, such as fatigue, cognitive impairments, and functional disability. Worry is a form of repetitive negative thinking focused on future events, and it may be a normal response to the uncertainty and life-altering effects of ABI. However, excessive worry and intolerance of uncertainty are linked to increased emotional distress and negative self-concept following injury. Cognitive and behavioral therapy (CBT) interventions that target worry and repetitive negative thinking have shown promise in reducing depression and anxiety symptoms in patients with ABI. However, barriers to accessing psychological therapy and a lack of knowledge about ABI and its emotional effects need to be addressed. Further research is needed to establish worry as a primary target for treating post-ABI psychopathology and to determine the specific role of worry and repetitive negative thinking in these conditions.