RATIONALE: Allergic reactions to NSAIDs are amongst the most common causes of reactions to non-prescription medications. Ibuprofen is one of the most commonly used NSAIDs. Herein, we describe a cohort of patients who presented with allergy to ibuprofen. METHODS: Consecutive patients were identified with ibuprofen allergy between 2008-2015 by retrospective chart review. These patients were characterized with respect to demographics, clinical characteristics of their reactions, number of ibuprofen reactions and anaphylaxis severity scores. This study was approved by the institutional REB. RESULTS: 36 patients were identified with allergy to ibuprofen confirmed on history. Females were more commonly affected (25F:11M). The mean age at first reaction was 33 years (range: 5-65). Patients had a mean of 2.31 reactions (range: 1-8) prior to diagnosis. Mean time from to onset was 70.18 minutes (range: 2-540). The mean duration of symptoms was 174.09 minutes (range: 20-690). Most patients had cutaneous involvement (89%); whereas 42% had upper airway and 42% had lower airway involvement. Cardiovascular manifestations were documented in 36% of patients. Anaphylaxis severity scores were calculated. Reactions were mild (grade 1 in 17/36), moderate (grade 2 in 18/36) and severe (grade 3 in 1/36). Co-existent asthma was associated with moderate to severe anaphylaxis to ibuprofen. CONCLUSIONS: Allergic reactions to ibuprofen are one of the most common causes of drug allergy. Patients most commonly affected are young females. Cutaneous involvement is almost always present, but many patients also report cardiopulmonary involvement. Most patients present with mild to moderate reactions, but reactions may be severe, especially in those with co-existent asthma.