BackgroundBeta-lactams are the most common antibiotic class reported to cause allergic drug reactions. Previous literature suggests an increased prevalence of penicillin drug allergy in female patients in both inpatient and outpatient settings. However, the effects of sex and gender have not been well characterized regarding the entire class of beta-lactam antibiotics. ObjectiveThis systematic review and meta-analysis aimed to identify sex and gender-based differences in the prevalence of immediate beta-lactam allergy. MethodsWe performed an electronic search of Ovid MEDLINE/PubMed, Embase, Web of Science, Scopus, and the Cochrane Library between 2013-2023. Patients with a documented beta-lactam allergy who underwent allergy testing with skin testing, oral drug challenge, or serum-specific IgE were included. We quantitatively assessed sex- and gender-based differences in beta-lactam allergy with meta-analysis. ResultsWe included 69 primary studies, assessing 53,989 participants from outpatient and inpatient cohorts. 7,558 patients had a confirmed beta-lactam allergy. There was no difference in the prevalence of positive beta-lactam allergy test between males and females. Sub-group analysis of studies that performed oral challenges did show a higher risk of beta-lactam allergy in females than males (RR 1.40, 95% CI 1.18-1.66, p < 0.001, I2 =77.8%). Finally, there was a higher proportion of females (64.8%) than males enrolled in beta-lactam allergy studies. ConclusionsOur findings suggest both sex-based and gender-based differences in the prevalence of immediate beta-lactam allergy. Both biological factors, such as sex hormones, and gender-based behaviors, including increased healthcare utilization, may contribute to higher rates of beta-lactam allergy diagnosis in females.