Recent studies on cashew nut allergy suggest that the prevalence of cashew nut allergy is increasing. Cashew nut consumption by allergic patients can cause severe reactions, including anaphylaxis. This review summarizes current knowledge on cashew nut allergy to facilitate timely clinical recognition and to promote awareness of this emerging food allergy amongst clinicians. The goal of this study is to present a systematic review focused on the clinical aspects of allergy to cashew nut including the characteristics of cashew nut, the prevalence, allergenic components, cross-reactivity, diagnosis and management of cashew nut allergy. The literature search yielded 255 articles of which 40 met our selection criteria and were considered to be relevant for this review. The 40 articles included one prospective study, six retrospective studies and seven case reports. The remaining 26 papers were not directly related to cashew nut allergy. The literature suggests that the prevalence of cashew nut allergy is increasing, although the level of evidence for this is low. A minimal amount of cashew nut allergen may cause a severe allergic reaction, suggesting high potency comparable with other tree nuts and peanuts. Cashew allergy is clearly an underestimated important healthcare problem, especially in children.