Allergic rhinitis and allergic conjunctivitis are so frequently associated that the need to coin a new name to describe the simultaneous manifestations generated the term allergic rhinoconjunctivitis. The significant impact of rhinoconjunctivitis on the quality of life and the wellbeing of the patients is the reason why the medical community shows a great interest to this disease. Another aspect is the financial burden that is not negligible. The anatomical connection between the organs involved facilitates the propagation of the disease. The allergic pathophysiological mechanisms implicated in allergic rhinitis and conjunctivitis also share common features. The diagnosis of rhinoconjunctivitis is based on the concordance between the symptoms, the clinical examination, and the diagnostic tests that should reveal the existence of an allergen specific IgE in vivo or in vitro. Whilst the nasal smear for eosinophils is considered a reliable diagnostic test for allergic rhinitis, the occurrence of eosinophils in the conjunctive is not a trustworthy indicator of allergy. The therapy of allergic rhinoconjunctivitis is based on patient education, pharmacotherapy, and allergen-specific immunotherapy. The local treatment for the allergic rhinitis is primarily based on topical corticosteroids that also manage the ocular symptoms. The first line of treatment of the ocular manifestations is represented by topical antihistamines and mast-cell stabilizers or double action drugs.