INTRODUCTION: Non-steroidal anti-inflammatory drugs are associated with a dose and duration-dependent coronary risk. There is little information concerning analgesic-dose ibuprofen, among the most widely used drugs worldwide. OBJECTIVE: Our objective was to measure the risks of acute coronary syndrome (ACS) after dispensing of ibuprofen, versus paracetamol. METHODS: Propensity score 1:2-matched cohorts of ibuprofen or paracetamol treatment episodes (TEs) in Echantillon Generaliste de Beneficiaires (EGB), the 1/97 sample of Systeme National des Donnees de Sante (SNDS), the French nationwide claims database, from 2009 to 2014, were compared. Outcomes were hospital admissions for ACS during the 3 months after the dispensing of ibuprofen or paracetamol. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated overall and stratified on low-dose aspirin dispensing. RESULTS: A total of 315,269 ibuprofen TEs in 168,400 persons were matched to 630,457 paracetamol TEs in 395,952 patients. Event rates were 50-100 times higher in low-dose aspirin users (27 vs 0.28 per 1000 patient years). Overall there was no difference in risk of ACS at 3 months (HR 0.94, 95% CI 0.74-1.20) despite a transient increase in the first 2 weeks in ibuprofen users (HR 1.70, 95% CI 1.11-2.59). In the stratified analysis, this short-term risk was only found in aspirin users (5% of population, HR 1.84, 95% CI 1.24-3.24), but not in non-aspirin users (HR 1.09, 95% CI 0.40-2.94). CONCLUSIONS: There was no evidence for an increased risk of ACS in patients dispensed ibuprofen compared to paracetamol.Read less <