Background: A significant part of the developmental delay (DD) population has epilepsy (26-70%) and live in an institution. These patients tend to have atypical presentation of epileptic seizures with higher risk of misdiagnosis. Distinguishing their ictal events from paroxysmal behaviors can be challenging.There often is a lack of description of the spells or inadequate history from the caregivers or the patients. These patients often have drug resistant epilepsy requiring polypharmacy with increased risk of morbidity and mortality. The aim of this study was to determine usefulness of Epilepsy Monitoring Unit (EMU) in diagnosis and management of these patients. Methods: This is a retrospective observational study of the patients with epilepsy and DD living in institutions that were admitted to the EMU. Results: Four patients met the inclusion criteria for this study. The mean age was 45(29-71), 3/4 (N=3) were male and 3/4 had focal epilepsy. All patients had mood disorders and 2 were taking antipsychotic medication. The mean admission-time was 6,25 days

(2-15) and there was a correlation with the events and seizures in 2/4 of the patients and the rest had a combination of behavioural-changes and seizures. Conclusions: EMU admission can provide an accurate diagnosis of spells in patients with DD and epilepsy, and improve their quality of life.