Levels of smoking and smoking initiation have been found to increase during the transition to adulthood. Symptoms of depression and anxiety may both precede or follow smoking behavior, yet there is equivocal evidence regarding the direction of this relationship. The aim of the current study was to examine the direction of this relationship in a group of young adult backpackers who traveled to social environments which are permissive of smoking. The current study involved a quasi‐experimental design examining 199 (52% men, mean age 24.27, SD = 1.05 years at time 1) young adults, before, during and following a backpacking experience of at least six months. Regression analyses was used to examine the association between smoking and symptoms of depression and anxiety over time. Relative to smoking levels before the journey, a significant transient increase in smoking was found during the journey. The increase in smoking during the journey predicted increases in both depressive and anxiety symptoms following the journey. The reverse direction models were not significant. Our study suggests that social contexts which are permissive of smoking, such as backpacking, increase young adult smoking behavior. Mood symptoms did not contribute to the observed increase in smoking behavior but, inversely, increases in smoking contributed to heightened mood symptoms. Additional longitudinal studies are needed to explore the role that smoking behavior plays in young adults’ mental health.