Postprandial hypotension (PPH) refers to a decrease in systolic blood pressure by ≥20 or to <90 mmHg from baseline ≥100 mmHg within 2 h of a meal. Previous studies have reported an association between diabetes and PPH; however, the characteristics of PPH in patients with diabetes remain unclear. We recruited patients with diabetes who regularly attended the diabetes outpatient clinic. Participants were instructed to carry out three sets of blood pressure measurements at six time points: just before and right after, and 30, 60, 90 and 120 min after their main meal of the day. Data on PPH symptoms were collected during an interview. To investigate the relationships between explanatory variables, PPH and associated symptoms, we carried out multiple logistic regression analyses. We analyzed data from 300 participants. There were 150 (50.0%) participants with PPH. Systolic blood pressure before a meal was significantly associated with PPH (odds ratio [OR] 1.56, 95% confidence interval [CI] 1.30-1.86, P < 0.001), after adjusting for covariates. Furthermore, age (OR 1.08, 95% CI 1.01-1.16, P = 0.027), hemoglobin A1c level (OR 2.39, 95% CI 1.01-5.64, P = 0.030) and coefficients of variation of R-R intervals (OR 0.79, 95% CI 0.65-0.97, P = 0.032) were significantly associated with asymptomatic PPH. Half of the present study outpatients with diabetes had PPH. High systolic blood pressure before a meal was significantly associated with the risk of PPH. Older adults and patients with higher levels of hemoglobin A1c or an autonomic dysfunction might have difficulties recognizing symptoms of PPH. © 2020 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.