Introduction. Increasingly physical activity (PA) is being recognized as an important outcome in non–small cell lung cancer (NSCLC). We investigated PA using novel global positioning system (GPS) tracking individuals with NSCLC and a group of similar-aged healthy individuals. Methods. A prospective cross-sectional multicenter study. Fifty individuals with NSCLC from 3 Australian tertiary hospitals and 35 similar-aged healthy individuals without cancer were included. Individuals with NSCLC were assessed pretreatment. Primary measures were triaxial accelerometery (steps/day) and GPS tracking (outdoor PA behavior). Secondary measures were questionnaires assessing depression, motivation to exercise, and environmental barriers to PA. Between-group comparisons were analyzed using analysis of covariance. Results. Individuals with NSCLC engaged in significantly less PA than similar-aged healthy individuals (mean difference 2363 steps/day, P = .007) and had higher levels of depression ( P = .027) and lower motivation to exercise ( P = .001). Daily outdoor walking time ( P = .874) and distance travelled away from home ( P = .883) were not different between groups. Individuals with NSCLC spent less time outdoors in their local neighborhood area ( P < .001). A greater number of steps per day was seen in patients who were less depressed ( r = .39) or had better access to nonresidential destinations such as shopping centers ( r = .25). Conclusion. Global positioning system tracking appears to be a feasible methodology for adult cancer patients and holds promise for use in future studies investigating PA and or lifestyle behaviors.