Background: Increases in public expenditures to general practitioner (GP) services and specialist care have spurred debate over whether to implement user fees for healthcare services such as GP consultations in Denmark. Objective: The objective of this study was to examine Danish patients’ attitudes towards user fees and their willingness to pay (WTP) for a consultation, and to investigate how user charges may impact patients’ behaviour. Methods: A questionnaire survey was conducted in a GP clinic. Results: A total of 343 individual persons answered the questionnaire. One hundred and seventy (50%) persons were not willing to pay for a consultation. Among patients reporting positive WTP values, the mean WTP was 137 (standard deviation 140) Danish kroner (DKK). Patients who were 65 years old or older were more likely to be willing to pay for a GP consultation than patients under the age of 65 years. Furthermore, patients with a personal annual income of more than 200,000 DKK were more likely to be willing to pay for a consultation than other income groups. With respect to patients with a positive WTP value, their own assessment of the seriousness of the consultation and their self-assessed health influenced the amount they would be willing to pay. Finally, we observed a stated willingness to substitute GP consultations with alternatives that are free of charge. Conclusion: About half of the patients with an appointment for a GP consultation are willing to pay for the consultation. User charges may potentially influence the patients’ behaviour. ClinicalTrials.gov NCT01784731.