Primary wake disorders encompass various conditions of excessive daytime sleepiness and / or increased nightmare sleep, of unknown origin beginning most often in adolescence and of recurrent natural history. Kleine in 1925 [1] and Levin in 1936 [2] described an episodic disorder characterized by periodic hypersomnolence, excessive eating and be-havioural changes. For days and weeks, the patients, mostly adolescent boys, sleep for eighteen or more hours from which they can be aroused. This awakening is long enough to eat, attend to toilet activities and is usually marked by withdrawal from social contacts and they return to bed at the first opportunity. Emotional stress and febrile illness occasionally precipitate episodes of hypersomnolence. The patient appears dull, often confused, restless and may display apathy, irritability, preference for sweets, incoherent speech, loss of sexual inhibitions, delusions, hallucinations, excitation or depression, slowness in thinking and subsequent poor memory of the episode. We report one such case. Case Report 14 year old son of a serving soldier was referred to psychiatric OPD of a large Military Hospital by medical specialist on 15 Feb 2000 with history of fever for two days, one week ago and since then the boy was withdrawn, did not talk cr play and felt like sleeping all the time. The boy complained of feeling sleepy all the time. Detailed history given by the mother elucidated that the patient had a low grade fever on 8 Feb 2000, for which he was given treatment from the MI Room and the fever subsided within two days. Following fever, the patient was noticed to be sleeping excessively, lethargic, was not studying, while earlier, he was quite studious. He used to get up to eat food that too on coaxing, hurriedly did toilet activities and again used to sleep. When he was sent to school forcibly with his elder brother, the report came that he keeps on sleeping in the class, does not read, write or play with other children. The mother also reported that although her son can be woken up from sleep, he remains drowsy, irritable, looks as if lost in thoughts and immediately goes back to sleep at the first opportunity and starts snoring (goes to deep sleep). She also noticed that he eats a lot of sweets during this period. She also reported that her son had similar episode of hypersomnolence following a bout of febrile illness for two days in Nov 99. He had recovered completely from this episode within a period of two weeks or so. When this happened for the second time she got worried and brought the child to hospital. General physical examination and systemic examination of the child was within normal limits. Mental status examination revealed a drowsy child who spoke in monosyllables and told that he was feeling sleepy. He was irritable, apathetic and did not cooperate during formal tests of cognitive functions. His sleep and appetite were increased. He did not have any delusions, hallucinations or depressive cognitions. The patient was investigated and haematological, urinalysis, biochemical parameters, ECG, EEG, CECT brain and MRI brain were within normal limits. A referral was made to the neurophysician to look out for any organic basis for this condition. A repeat EEG done was also normal. Clinically, the patient was diagnosed as a case of Kleine Levin Syndrome and he was serially reviewed in the psychiatric OPD. The mother of the child was reassured, psychoeducation was given about the nature of the illness and its course and prognosis, to allay her anxiety. The child started improving gradually, he was asymptomatic by 24 Feb 2000, and he had poor memory of the episode. The patient is being reviewed periodically and he is maintaining improvement.