The phenomenology and underlying pathophysiology of bipolar disorder (BD) are heterogeneous. The identification of putative endophenotypes for BD can aid in the investigation of unique patho-etiological pathways, which may lead to the development of personalised preventative and therapeutic approaches for this multi-faceted disorder. We included original studies involving unaffected first-degree relatives of BD patients (URs) and a healthy control (HC) comparison group with no first-degree family history of mental disorders, investigating: ‘cold’ and ‘hot’ cognition and functional and structural neuroimaging. Seventy-seven cross-sectional studies met the inclusion criteria. The present review revealed that URs in comparison with HCs showed: (i) widespread deficits in verbal memory, sustained attention, and executive function; (ii) abnormalities in the reactivity to and regulation of emotional information along with aberrant reward processing, and heightened attentional interference by emotional stimuli; and (iii) less consistency in the findings regarding structural and resting state neuroimaging, and electrophysiological measures.