Objectives Recent years have witnessed a progressive increase in defensive medicine (DM) in several Western welfare countries. In Danish primary and secondary care, documentation on the extent of DM is lacking. Before investigating the extent of DM, we wanted to explore how the phenomenon is understood and experienced in the context of general practice in Denmark. The objective of the study was to describe the phenomenon of DM as understood and experienced by Danish general practitioners (GPs). Design A qualitative methodology was employed and data were generated through six focus group interviews with three to eight GPs per group (n=28) recruited from the Region of Southern Denmark. Data were analysed using a thematic content analysis inspired by a hermeneutic-phenomenological focus on understanding and meaning. Results DM is understood as unnecessary and meaningless medical actions, carried out mainly because of external demands that run counter to the GP's professionalism. Several sources of pressure to act defensively were identified by the GPs: The system's pressure to meet external regulations, demands from consumerist patients and a culture among GPs and peers of infallibility and zero-risk tolerance. Conclusions GPs understand DM as unnecessary and meaningless actions driven by external demands instead of a focus on the patient's problem. GPs consider defensive actions to be carried out as a result of succumbing to various sources of pressure deriving from the system, the patients, the GPs themselves and peers.