A strict relationship between allergic rhinitis and allergic asthma has been seen recently, and in many ways respiratory allergy could be seen as a single disorder of the airways. The link between rhinitis and asthma can be elucidated only by studying the natural history of the disease over long periods. We describe the follow-up of 99 allergic patients up to 10 years and the evolution of their disease. Ninety-nine patients (50 male, 49 female, mean age 31 years) out of 142, suffering from allergic rhinitis or allergic asthma, could be monitored up to 10 years after the initial diagnosis. Demographics, sensitizations and smoke habit were assumed as evaluation parameters. At baseline, 44 patients suffered from AR alone, 12 from AA alone and 43 from AR+AA. After 10 years, 31.8% of the AR patients developed developed AA and 50% of the patients with AA developed AR. Only the familial history for atopy significantly influenced the disease's evolution, whereas gender, age, smoking habit and skin sensitization did not. Sixty-five percent of patients with a single sensitization at the beginning developed new sensitizations. In conclusion, this long-term survey confirms that a relevant percentage of patients with AR alone or AA alone have a progression of the disease.