This paper reports an 8-yr retrospective study on the effects of an uninterrupted procedure of transition of 73 adolescents with Type 1 diabetes from the Paediatric to the Adult Clinic held in the same hospital. Interviewed patients had a mean age of 21.0+/-0.95 yr at transition. Patients were satisfied with the information received before transition (100%), and appreciated being introduced to the adult physician prior to being transferred (92%), and having found their paediatrician during the first visit at the Adult Clinic (100%). Consensus for transition was attained after 2-4 consultations in 66.6% of patients. Seventy-nine percent of patients considered 20 yr of age as an appropriate age to be transferred. Patients confirmed to have found at the Adult Clinic: privacy (85%), confidentiality (95%), short waiting times (78%), informal atmosphere (100%), and the same consultant (100%). Only 3% of patients tried to go back to the Paediatric Clinic but they were discouraged. Clinic attendance rate ranged between 92 and 100%. We consider that the key factors for a successful process of transition from a Paediatric to an Adult Clinic are: age at transfer around 20 yr, smooth movement within the same hospital, consensus of patients and their parents, prior personal contact with the adult physician, paediatrician attendance at the first visit at the adult service and his unambiguous role against all attempts to go back to the paediatric service and, finally, the availability of the same physician at out-patient clinic visits.