We conducted a pilot study for a quantitative survey among chronically ill adolescents and their parents. Our main objectives were to assess the use of an online questionnaire to collect data on the transition process from pediatric to an adult care and to evaluate the willingness to answer in our target population. A total of 183 adolescents and their parents were contacted by sending them three postal letters (an invitation to participate and two reminders about 3 and 9 weeks after the invitation). Before the second reminder, we only offered the option to use an online questionnaire, and the response rate stayed very low, only slightly above 10%.