The rise in the prevalence of asthma and COPD, the expected decline in the number of respiratory specialists, and the availability of spirometers in primary care raise the question of whether future general practitioners should carry out this test. This study assessed the theoretical and practical knowledge of French general practice trainees. Once divided into four groups (1: theoretical and practical knowledge; 2: theoretical knowledge; 3: practical knowledge; 4: insufficient theoretical and practical knowledge), the following six explanatory variables were analysed: gender, personal awareness of these diseases, theoretical and practical training, access to respiratory function testing centres, and completion of a respiratory medicine placement during the DES. The analysis covered 1,261 trainees across 29 universities. Only 4.3 per cent (54) of the junior doctors were in group 1. These were mainly men who had completed a respiratory medicine rotation during their junior doctor training. There is a significant need for training. Teaching should prioritise practical learning and expand respiratory medicine rotations.