Introduction Increased postprandial glucose (PPG) is associated with high glycated haemoglobin levels and is an independent risk factor for cardiovascular diseases. The aim of this study was to compare PPG increments in Asian versus non-Asian adults with type 2 diabetes (T2D), who were insulin-naive or insulin-experienced, from the phase 3 insulin degludec/insulin aspart (IDegAsp) clinical trials. Methods This was a post hoc analysis of data from 13 phase 3, randomised, parallel-group, open-label IDegAsp trials in patients with T2D. The pooled baseline clinical data were analysed for insulin-naive and insulin-experienced groups; and each group was split into subgroups of Asian and non-Asian patients, respectively, and analysed accordingly. Baseline self-monitored blood glucose (SMBG) values at breakfast, lunch and the evening meal (before and 90 min after each meal) were used to assess PPG increments. The estimated differences in baseline SMBG increment between the Asian and non-Asian subgroups were analysed. Results Clinical data from 4750 participants (insulin-naive, n = 1495; insulin-experienced, n = 3255) were evaluated. In the insulin-naive group, the postprandial SMBG increment was significantly greater in the Asian versus the non-Asian subgroup at breakfast (estimated difference 28.67 mg/dL, 95% confidence interval [CI] 18.35, 38.99; p < 0.0001), lunch (17.34 mg/dL, 95% CI 6.47, 28.21; p = 0.0018) and the evening meal (16.19 mg/dL, 95% CI 5.04, 27.34; p = 0.0045). In the insulin-experienced group, the postprandial SMBG increment was significantly greater in the Asian versus non-Asian subgroup at breakfast (estimated difference 13.81 mg/dL, 95% CI 9.19, 18.44; p < 0.0001) and lunch (29.18 mg/dL, 95% CI 24.22, 34.14; p < 0.0001), but not significantly different at the evening meal. Conclusion In this post hoc analysis, baseline PPG increments were significantly greater in Asian participants with T2D than in their non-Asian counterparts at all mealtimes, with the exception of the evening meal in insulin-experienced participants. Asian adults with T2D may benefit from the use of regimens that control PPG excursions.