Since its development and theorisation in the 60s, attachment theory has greatly influenced both clinical and developmental psychology suggesting the existence of complex dynamics based on the relationship between an infant and its caregiver, that affects personality traits and interpersonal relationships in adulthood. Many studies have been conducted to explore the association between attachment styles and psychosocial functioning and mental health. By contrast, only a few studies have investigated the neurobiological underpinnings of attachment style, showing mixed results. Therefore, in this review, we described current evidence from structural and functional imaging studies with the final aim to disentangle the neural correlates of attachment style in healthy individuals. Overall, different attachment styles have been correlated with volumetric alterations mainly in the cingulate cortex, amygdala, hippocampus and anterior temporal pole. Consistently, functional imaging studies suggested patterns of activations in fronto-striatal-limbic circuits during the processing of social and attachment-related stimuli. Further studies are needed to clarify the neurobiological signature of attachment style, possibly taking into consideration a wide range of demographic, psychosocial and clinical factors that may mediate the associations between the style of attachment and brain systems (e.g., gender, personality traits, psychosocial functioning, early-life experience).