Sublingual immunotherapy (SLIT) is indicated in the treatment of allergic rhinitis and asthma. However, an issue scantly investigated is the patients satisfaction and the consequent compliance. This study is aimed at evaluating the possible differences of SLIT administered continuously or intermittently on several parameters: clinical efficacy, Quality of Life (QoL), satisfaction, compliance and safety. Forty allergic patients were treated for 12 months. The treatment was carried out by sublingual administration of an allergen extract of a 50% mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae at 10 and 300 IR/ml concentrations. Patients were randomly treated continuously or intermittently (i.e. 2 month treatment alternate to 2 month suspension). Both schedules were significantly effective in reducing allergic symptoms and improving QoL. Compliance and satisfaction were good in both groups. Local and systemic reactions were few, self-resolving, and mild in both schedules. Intergroup analysis did not reveal any difference between the two groups regarding these parameters. In conclusion, this preliminary study provides the evidence that also intermittent SLIT is as effective and safe as traditional continuous treatment. In addition, compliance and satisfaction are super-imposable in the two groups.