Evidence exists that women and people from low- and middle-income countries are under-represented on the editorial boards of medical journals. This may adversely influence the journal output. We conducted a pooled, cross-sectional evaluation of the editorial board membership of anaesthesia journals. We collected data on members of editorial boards from the founding year and at 5-yearly intervals until 2020. For each editor, we recorded gender, country of affiliation, World Bank income classification (1990 onwards) and editorial role (2020 only). The composite editorial board diversity score was calculated for each editorial board. We obtained complete data for the composition of editorial boards from all 30 journals for 2020, but for only 171 out of 304 editorial boards (56%) over the time period examined. In 2020, 409 out of 1973 (21%) were women (range across the editorial boards 0-39%) and 139 out of 1982 (7%) were from low-, low-middle- and upper-middle-income countries (range across the editorial boards 0-71%). In 2020, of editorial board positions with known seniority status, 109 out of 259 (42%) of women and 306 out of 960 (32%) of men were in senior roles. In the same year, 397 out of 1115 (36%) of people from high-income countries were in senior roles, compared with 19 out of 93 (20%) of people from upper-middle-income countries and 0 out of 14 (0%) people from lower-middle-income countries. The median composite editorial board diversity score was 4 (range 2-6) in 2020 - 5 or less suggests poor diversity, while 8 or more suggests good diversity. Women and people from low- and middle-income countries are under-represented on anaesthesia journal editorial boards. The editorial boards do not reflect the anaesthesia workforce and may act as a barrier to the publication of research produced by these groups. Urgent action is required to improve diversity.