Although data indicate that e-cigarettes are the most commonly used tobacco product among adolescents and young adults (AYAs), frequent co-use with combustible cigarettes and cannabis products causes difficulty in disentangling associated risk of asthma and related respiratory symptoms. To examine associations between e-cigarette, cigarette, and cannabis use with self-reported asthma diagnosis, shortness of breath (SOB), and wheeze, researchers conducted a web-based survey in August 2020 of a sample of United States AYAs with a mean age of 18.9. Among past 30-day current e-cigarette users, 15% and 37% reported current cigarette and cannabis use, respectively. Past 3-day e-cigarette use was associated with increased odds of self-reported asthma (odds ratio [OR], 1.4), wheeze (OR, 3.1), and SOB (OR, 2.9) after controlling for age, sex at birth, and race/ethnicity, when compared with never e-cigarette use. Although past 30-day e-cigarette use was no longer associated with asthma (OR, 1.11) after controlling for past 30-day cigarette and cannabis use, associations remained with increased wheeze (OR, 2.3) and SOB (OR, 2.1)