Dengue fever, a mosquito-borne virus, is an ongoing public health issue in North Queensland. Importation of dengue fever by travellers visiting or returning to Australia can lead to epidemics. The mosquito can acquire the virus in the symptomatic viraemic phase, so timely recognition of cases is important to prevent epidemics. There is a gap in the literature about backpackers’ knowledge of dengue fever and the decision-making process they use when considering utilising the Australian health-care system. This study uses grounded theory methods to construct a theory that explains the process backpackers use when seeking health care. Fifty semi-structured interviews with backpackers, hostel receptionists, travel agents and pharmacists were analysed, resulting in identification of a core category: ‘weighing up the costs of seeking health care’. This core category has three subcategories: ‘self-assessment of health status’, ‘wait-and-see’ and ‘seek direction’. Findings from this study identified key areas where health promotion material and increased access to health-care professionals could reduce the risk of backpackers spreading dengue fever.