Diabetes is a common chronic disease with various complications. The present study was conducted to determine the association of plant-based dietary index (PDI) and dietary acid load (DAL) with sleep status as well as mental health in type 2 diabetic women. In this cross-sectional study, a validated food frequency questionnaire was used to assess dietary intakes of 230 diabetic patients. We created a whole PDI, healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI). DAL was calculated based on potential renal acid load and net endogenous acid production method. The Pittsburgh Sleep Quality Index and 21 items Depression, Anxiety and Stress Scale were used to assess sleep and mental health disorders, respectively. Participants in the top group of uPDI had greater risk of poor sleep (OR: 6.47, 95%CI: 2.75-15.24). However, patients who were in the top group of hPDI had a lower risk of sleep problems (OR: 0.28; 95%CI: 0.13-0.62). Participants in the top group of uPDI had greater risk of depression, anxiety and stress (OR: 9.35, 95%CI: 3.96-22.07, OR: 4.74, 95%CI: 2.28-9.85, OR: 4.24, 95%CI: 2.14-8.38, respectively). In conclusion, participants with higher DAL scores and patients who adhered to animal-based diets rather than plant-based diets were likely more to be poor sleepers and have mental health disorders.