Objective: Ibuprofen is as effective as paracetamol (acetaminophen) as an antipyretic and analgesic agent in paediatric patients. Ibuprofen is considered to be well tolerated; however, there are reports on gastrointestinal bleeding or renal adverse effects among children treated with ibuprofen. Oral ibuprofen suspension was recently registered and approved by the Ministry of Health in Israel as an antipyretic and analgesic agent. Before distribution of the drug to pharmacies, we aimed to follow possible adverse effects among children receiving ibuprofen suspension in several paediatric wards and clinics. Design: Children with fever needing antipyretic medication received ibuprofen oral suspension 5 to 10 mg/kg/dose. In each case the age of the patient, gender, diagnosis, number of ibuprofen doses, duration of treatment and any adverse reactions were reported. Results: 1564 children from 14 paediatric wards (11 hospitals) and from five paediatric and family clinics participated in the study; 882 males and 682 females. The patients, aged 3.6 ± 4.2 years (range 1 month to 16.5 years), received 2.4 ± 3 (range 1 to 22) doses of ibuprofen suspension for 1.56 ± 2.11 (range 1 to 20) days. Adverse reactions were reported among 26 patients (1.66%) [95% confidence interval (CI) 1.1-2.4]; 18 children (1.15%) [95% CI 0.7-1.8] vomited immediately after the administration of the drug and it was not readministered. Two children (0.12%) [95% CI 0.02-0.46] had abdominal pain that resolved spontaneously, two patients reported nausea, and two other children had diarrhoea. Eight children (0.51%) reported experiencing a 'bitter taste' from the medication, of whom one patient discontinued the medication while the other seven continued it. Conclusions: The adverse reactions following administration of oral ibuprofen suspension reported in our study were low in frequency, mild and disappeared spontaneously. However, continuing reporting on its tolerability is needed.