Hypoglycaemia, common in diabetic patients treated with insulin, can induce various neurological disturbances. Of these, seizures are the most common acute symptom, mainly of the generalised tonic-clonic type, with focal events only exceptionally being reported and documented. Hypoglycaemia can modify cortical excitability by determining an imbalance between excitation and inhibition; some brain structures, such as the temporal lobe and hippocampus, appear to be particularly susceptible to this insult. We describe a case of a 61-year-old diabetic patient in whom insulin-induced transient hypoglycaemia triggered a focal seizure of temporal origin that was well documented by EEG during 24-hour ambulatory monitoring. This is, to our knowledge, one of the few, well-documented cases of this type of seizure.