We describe a 5-year-old girl who had sudden onset difficulty in walking after 3 days of febrile illness. In the emergency department her creatine kinase level was elevated but urine myoglobin was normal. She was diagnosed as having benign acute childhood myositis. Because of poor oral intake and dehydration, she was admitted to the pediatric ward. The next day she had a petechial rash over the antecubital fossa, and dengue IgM back was positive. She was treated conservatively and recovered uneventfully. Despite dengue fever being endemic in Malaysia, this is the first case report of myositis following dengue infection in Malaysia.