Introduction: The perception of negative health consequences is a common motive for quitting smoking, but specific information on the immediate health effects of occasional smoking among young adults is limited. Method: To examine the relationship between cigarette use and symptoms of (a) cough or sore throat and (b) shortness of breath or fatigue after regular activities among young adults, we performed online health screening of a random sample of 25,000 college undergraduates. The screening survey assessed demographic characteristics, smoking and related health behaviors, and respiratory symptoms in the previous 30 days. Results: The response rate was 26% (6,492/25,000). Among individuals reporting no smoking in the prior 30 days and smoking on 1-4, 5-10, 11-20, or 21-30 days, the prevalence of one or more days of cough/sore throat increased from 62.5% to 68.3%, 72.0%, 71.4%, and 73.7%, respectively (p < .001). Similarly, the prevalence of shortness of breath/fatigue increased from 42.7% to 47.1%, 56.2%, 59.5%, and 64.6%, respectively (p < .001). After controlling for demographics, other important health behaviors (e.g., days consuming alcohol and getting adequate sleep), and environmental tobacco smoke (ETS) exposure, reporting symptoms of cough/sore throat was associated with smoking on at least 21 days, whereas shortness of breath/fatigue was associated with smoking on 5 or more days. Among those reporting symptoms, increased number of days with respiratory symptoms was associated with smoking on most days as well as ETS exposure. Discussion: In conclusion, this cross-sectional study found that occasional smoking and ETS exposure were associated with an increase in the rate of respiratory symptoms (cough/sore throat and shortness of breath/fatigue) among young adults.