This study reviews the published research on night time eating, including the night eating syndrome (NES) and the nocturnal eating/drinking syndrome (NEDS). Studies were identified by a computerized literature search (PubMed, PsycInfo) and by references from the papers obtained. In addition, published abstracts from recent conferences in the areas of eating disorders and obesity were included. Individual studies were reviewed and their results summarized. Wakeful night time eating appears to be a frequent symptom which is more common among the obese. The data suggest an early age of onset with a chronic course in many patients. There appears to be considerable overlap between NES and NEDS. Treatment studies are sparse. The clinical features of these syndromes, their comorbidities, and their prevalence rates remain a matter of debate. It is unclear if the night eating syndrome presents a distinct entity that is of clinical relevance. The current nosologies may not capture the natural clustering of eating and sleep-related pathology as it occurs in general population samples. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association.