The aim of our study was to evaluate the frequency of hypoglycaemia unawareness and the continuous glucose profile in a group of subjects with Type 1 diabetes (T1D) with repeated non-severe/severe hypoglycaemia. Twenty patients (aged 35.2 +/- 7.6 years, duration of disease 16.4 +/- 6.4 years) were included. Hypoglycaemia awareness was evaluated using questionnaires and after an acute-induced hypoglycaemia. Glucose profile was studied using 72-h continuous glucose monitoring (CGM). All subjects were classified as having hypoglycaemia unawareness by questionnaires. Four patients displayed a "normal" signs/symptoms response to hypoglycaemia. The CGM revealed 18% of the measurements <70 mg/dl and this percentage was correlated with questionnaire score (r = 0.55, P < 0.035) and with the increase in the percentage of signs/symptoms during the induced hypoglycaemia (r = -0.57, P < 0.015). In patients exhibiting an "abnormal" response during hypoglycaemia, CGM values <70 mg/dl was higher (22.6 +/- 8.4%) than in those with a "normal" response (10.2 +/- 9.0%; P < 0.028). Summarising, in subjects with T1D and repeated hypoglycaemia the frequency of impaired awareness is substantially common. Its presence is related to a high proportion of ambulatory glycaemic profile below the desirable range.