AIM To study the long-term use of self-study material in type 1 diabetes patient education targeted at the prevention of severe hypoglycaemia. METHODS Randomized 1:1:1 control study in three local hospitals. We studied 332 type 1 diabetes patients from the geographic population, aged 2.6-18.9 y at entry. The intervention group received a videotape and brochure in which interviewed patients, parents and medical experts reviewed in detail practical skills for self-control and treatment, with the aim of preventing severe hypoglycaemia. There were two control groups: one received a videotape and brochure with general diabetes information and the other only traditional treatment. Primary endpoints were severe hypoglycaemia needing assistance by another person and HbA1c. Dissemination, reading/viewing level, patients' attitudes and extra contact with caregivers were also investigated. At 24 mo, 249 subjects provided data. RESULTS The yearly incidence of severe hypoglycaemia decreased at 24 mo from 42% to 25% (difference 17%, 95% CI 3-31, p = 0.0241) in the intervention group, but not in controls. HbA1c remained unchanged. Video use during months 13-24 was higher in the intervention group than in controls (p = 0.0477), ranging from 1-15 (median 2) times, among 37% of patients (months 1-12, 100%). Higher future use was anticipated for intervention material (p = 0.0003). Extra caregiver contact was related to severe hypoglycaemia (p = 0.0009). The cost of the material was <EUR 10 per patient. CONCLUSION Mass-distributed pedagogical devices such as high-quality video programmes and brochures may reach high dissemination levels and, when targeted, contribute to the prevention of severe hypoglycaemia over a longer period of time, being a cost-effective complement to traditional care.