Background: Fever is a natural response to infection that annually hosts approximately 70 % of preschool children. Acetaminophen is widely used as an antipyretic drug with high efficiency and safety. Ibuprofen is one of the Propionic acid derivatives in which like acetaminophen. Use paracetamol plus Ibuprofen increasingly used to treat fever associated symptoms, but it is unclear whether the combination of the two is better than using each alone or not. The aim of this study is comparison of Acetaminophen and ibuprofen to control fever with the combination of both. According to a study conducted by Alastair D Hay and colleagues, 540 patients with fever higher than 38 entered to the study. The patients randomized into three groups to receive acetaminophen, ibuprofen and acetaminophen + ibuprofen. Before taking the drugs were measured fever and consequently after 2, 4 and 6 hours fever temperatures were measured. Information about each patient included age, sex , weight , temperature, duration of fever , antibiotics , acetaminophen or ibuprofen before you go to the doctor , appetite , sleep , activity of disease at diagnosis, history of asthma , a history of febrile seizures in the past, they will be excluded and patients will be enrolled who have previously received nothings . Information collected will be analyzed after entering in the SPSS program with one way Analysis of Variance and tukey test.