BACKGROUND Aspirin-induced asthma (AIA), is a distinct clinical syndrome affecting some asthmatic patients. Although the name of the condition relates to aspirin, it is well established that affected patients are cross-sensitive to all non-steroidal anti-inflammatory drugs (NSAIDs). OBJECTIVE Assessing the prevalence of AIA among Saudian asthmatic patients. METHODS This is a retrospective study of the medical records of asthmatic patients. RESULTS The prevalence of AIA in the patients studied was found to be 12.6%. Statistical analyses indicated that AIA was associated with more severe asthma [odds ratio (OR) (95% Confidence interval (CI)) in Group I cases 2.86 (1.24 to 6.59) respectively (p<0.05)]. The results showed that some allergic conditions were significantly more common in Group I for allergic rhinitis (OR=2.19, 95% CI 0.89-5.37, p<0.05), pollinosis (OR=1.59, 95% CI 0.85-2.98, p<0.05) for antibiotic allergy (OR=1.25, 95% CI 0.65-2.41, p<0.05) and for atopic dermatitis (OR=1.34, 95% CI 0.70-2.55, p<0.05). Family history of allergy had a more significant role in Group I cases (OR=1.27, 95% CI 0.68-2.37, p<0.05). No gender difference on asthma severity was detected in either group (Chi(2)=2.19, p>0.05). CONCLUSIONS The prevalence of respiratory symptoms triggered by aspirin/NSAID use was 12.6% in the asthmatics studied. AIA appears to be a significant problem and further investigations of the mechanisms of these responses and the possible link between this syndrome and other allergic co-morbidities are required.