ObjectivesIt has been argued that attachment theory could enhance our knowledge and understanding of psychotic phenomenology. DesignWe systematically reviewed and critically appraised research investigating attachment and psychotic phenomenology in clinical and non-clinical samples. MethodsWe searched databases Pub Med, PsycINFO, Medline and Web of Science using the keywords. Attachment, Adult Attachment, Psychosis, Schizotypy and Schizophrenia and identified 29 studies assessing adult attachment in combination with psychotic phenomenology. ResultThe findings indicated that both insecure anxious and insecure avoidant attachment are associated with psychotic phenomenology. Insecurely attached individuals are more vulnerable to developing maladaptive coping strategies in recovering from psychosis. The importance of attachment experiences for processing social information, mentalization skills and developing social relationships, including therapeutic relationships, in samples with psychosis is also highlighted. ConclusionAttachment style is a clinically relevant construct in relation to development, course and treatment of psychosis.