Narcolepsy with cataplexy is a chronic neuropsychiatric disorder associated with inappropriate control of rapid eye movement (REM) sleep. The main symptoms are excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, and disturbed nocturnal sleep. Cataplexy is marked by episodes of muscular weakness and may cause the patient to collapse to the ground. So far, pharmacotherapy of cataplexy and hypnagogic hallucinations has been predominantly based on tricyclic antidepressants. Recently, new drugs that block the reuptake of norepineprine and serotonin (e.g., venlafaxine) have been suggested as first-line treatment. These drugs have become our choice in treating children with cataplexy and nightmares as a symptom in narcolepsy. We describe clinical case reports of venlafaxine treatment in 6 children aged 7-12 years old when diagnosed with narcolepsy-cataplexy. In 2 cases with up to 50 daily cataplectic attacks, an initial effect of 37.5 mg of venlafaxine was initially observed. However, during the first year, the dose had to be increased to 112.5 mg daily to avoid cataplexy. A third patient with partial cataplexy was treated with 75 mg of venlafaxine daily. In 2 cases, hypnagogic hallucinations, described by the patients as nightmares, were the most troubling symptom and were successfully treated with only 37.5 mg of venlafaxine daily. Side effects included an increase of disturbed nocturnal sleep when venlafaxine was taken after 2:00 p.m. No major aggressive or suicidal thoughts and no raised blood pressure were recorded. Venlafaxine has proven to be an effective treatment of cataplexy and hypnagogic hallucinations in 6 children with narcolepsy. No severe side effects were observed.