With an increasing number of adolescents participating in international travel, little is known about travel-related behaviors and health risks in this age group. In the years 2015-2016, we conducted an anonymous, posttravel, questionnaire-based survey with the aim to compare self-reported practices and travel-related symptoms between adolescents (< 18 years old, N = 87) and adults (≥ 18 years old, N = 149) who came to our travel clinic before their humanitarian missions. They had the same pretravel health education, and traveled together to perform similar activities. In univariate analysis, compared with adults, we found that adolescents reported less prior international travel (P < 0.001), more often wore long-sleeved clothing for malaria prevention (P < 0.001) but less often for sun protection (P = 0.009), more often used insect repellents (P = 0.011), and less often had diarrhea (P = 0.024). All other practices and health outcomes were similar between the groups. Multivariate analyses using Bayesian network show strong associations between adults and prior travel experience, and not wearing long-sleeve clothing for malaria prevention. We also found strong associations between prior international travel and sustaining an injury, and having jet lag, as well as between taking malaria prophylaxis and not having diarrhea. Overall, most practices and health outcomes were similar between age groups. Adolescent age and lack of prior international travel experience did not have significant impacts on practices and health outcomes. Our findings highlight the need for more effective strategies to improve the behaviors and health outcomes in both adolescents and adults.