Background <p>High-intensity work environments and high psychological stress place anaesthesiologists in a state of chronic stress. T lymphocyte subsets are an essential component of the peripheral immune cells and are important in the pathophysiology of chronic stress. The aim of this study was to investigate the levels of psychological stress, the expression levels of circulating T lymphocyte subsets, and the correlation between them.</p> Methods <p>This study included 61 participants from two tertiary hospitals in Nanjing, China. The Chinese Perceived Stress Scale (CPSS), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7) scales were used to assess psychological stress levels. The percentage of circulating T lymphocyte subsets was determined using flow cytometry.</p> Results <p>The proportion of anaesthesiologists with high stress levels was 45.90%. The numbers of γδT cells, T helper 1 (Th1) cells, T helper 17 (Th17) cells, and the ratio of Th17/regulatory T (Treg) cells exhibit significant differences in T lymphocyte subsets across different psychological stress levels. γδT, Th1, and Th17 cell counts were higher in high-stress participants with anxiety and depression than in others.</p> Conclusions <p>High occupational stress is associated with negative emotions and may also affect some subsets of circulating T lymphocytes in young anaesthesiologists.</p> Trial registration <p>Chinese Clinical Trial Registry, ChiCTR1900021637. Registered on 2 March 2019, <a href="https://www.chictr.org.cn/showproj.html?proj=29630">https://www.chictr.org.cn/showproj.html?proj=29630</a>.</p>