A substantial group of patients with type 1 diabetes has difficulty adhering to the treatment regimen, and as a consequence is at increased risk of developing microvascular complications. Cognitive behavioural interventions may help these patients to cope more effectively with their diabetes. We developed a 4 weeks cognitive behavioural group training (CBGT) for patients with type 1 (insulin-dependent) diabetes in persistent poor glycaemic control, to help them overcome negative beliefs and attitudes towards diabetes and improve their self-care behaviours. Feasibility and efficacy of CBGT were tested in a non-randomised prospective study in 24 poorly-controlled type 1 diabetes patients (mean age 35.2 ± 11.1years; 15 female; mean HbA1c 9.3% (±1.2)), with assessments at 3 and 6 months follow-up. The programme was delivered in small groups (n = 6-8), by a team of a diabetes nurse specialist and a psychologist. Primary outcome measures were glycosylated haemoglobin (HbA1c), diabetes-related emotional distress (PAID) and psychological well-being (WBQ-12). Changes in diabetes self-care activities (DSCI) were documented, along with perceived barriers in diabetes questionniare (BDQ) and fear of hypoglycaemia survey (HFS). Data were analysed using repeated measures analysis of variance. The CBGT proved to be feasible in this selected group of patients and was well appreciated. Following CBGT, mean HbA1c dropped by 0.8% at 6 months from baseline, while emotional well-being was preserved. It is concluded that CBGT is a promising intervention that deserves further evaluation in randomised controlled trials.