Intentional insulin overdose in diabetic patients is a rather rare critical situation. We report the case of a patient suffering from type 1 diabetes who was found comatose with a plasma glucose close to zero after having injected herself massive doses of both aspart and glargine insulin analogues. The prevention of hypoglycaemic episodes in this patient required a long-term glucose infusion (i.e., 59 hours) which significantly exceeds the usual time-effect profile of glargine. This observation emphasizes again that clinicians should be aware of the extremely prolonged action of long acting insulin analogue glargine after intentional massive injection in order to avoid a too early interruption of glucose infusion and a subsequent risk of relapse of severe hypoglycaemic episodes.