BackgroundIncreased cannabis consumption worldwide challenges allergists because of an upsurge in cannabis allergy and need to discuss cannabis with patients. ObjectiveTo determine the knowledge, attitudes, and practices regarding cannabis among allergists and their approach to recognizing and diagnosing suspected cannabis allergy. MethodsThe International Allergist Canna Knowledge, Attitudes, and Practices Survey was completed by members from 3 International Allergy Societies. Survey questions included the following: 13 on cannabis attitudes, 7 on cannabis knowledge, and 4 on real-world allergy practices. Knowledge level was dichotomized and Statistical Package for the Social Sciences TwoStep Cluster Analysis grouped participants by attitudes. Multivariate analysis determined the relationship of knowledge and attitude to practice delivery. ResultsOf 570 eligible surveys started, 445 (78.1%) were completed. Participants were 49.7% of female sex, 65.9% aged 24 to 56 years, approximately 70% in practice for more than or equal to 10 years, and 29.2% practicing in an area where cannabis use is illegal. Of the respondents, 43.1% reported consulting on patients with suspected cannabis allergy and 54.7% had undertaken skin prick testing, in vitro cannabis testing, or both. Statistically significant differences were found between the 3 societies for most variables analyzed. Analysis of attitudes revealed 3 clusters named Traditional, Progressive, and Unsure. Those with more progressive attitudes toward cannabis and who had more knowledge were more comfortable speaking to patients about cannabis and more often asked patients on how often and how they used cannabis (all P < .001). ConclusionVarying knowledge and attitudes toward cannabis affecting comfort communicating with patients about cannabis were found in members of 3 allergy societies supporting the need for more cannabis research and education.