Molecular component-resolved diagnostics has established itself in recent years as an integral part of the routine diagnosis of allergic rhinitis. A systematic literature review was performed. By using allergen components appropriately, it is possible to identify IgE sensitizations to specific marker allergens and to crossreactive allergens and this way explain polysensitizations obtained in extract-based diagnostics. The detection of individual molecular sensitization patterns enables better classification of the clinical symptoms, thus enhancing the possibility of individual, personalized treatment planning. This implies greater diagnostic reliability for specific immunotherapy, which should in turn result in a better treatment response—despite there being no scientific evidence of this as yet. In spite of the immense expansion of our knowledge in the field of component-resolved diagnostics, the clinical relevance of molecular findings still needs to be consistently assessed on the basis of the individual patient’s symptoms. This paper is intended to provide a guide to—and highlight possible courses of action when—making appropriate use of individual components in the diagnosis of allergic rhinitis.