Performing self-care activities can be challenging but it is important for favourable outcomes of type 2 diabetes mellitus (T2DM). It may be influenced by psychological problems. Therefore, this study examined the level of self-care activities and the presence of psychological problems among patients with T2DM. The association between these activities and the psychological problems was assessed too. This cross-sectional study was conducted at a public health clinic in Sabah. Data was collected between July and September 2017 using a validated self-administered questionnaire which include the depression, anxiety and stress scale-21 (DASS-21) and the summary of diabetes self-care activities (SDSCA) questionnaire. About 91% of 331 participants took diabetes medications in ≥6 days per week. They followed a healthful eating plan, inspected feet and exercised 30 minutes a day in 5.0 (IQR 4.0), 4.0 (IQR 7.0) and 1.0 (IQR 4.0) days per week respectively. Among owners of glucometer, the median (IQR) of monitoring blood glucose was 1.0 (1.0) days per week. The participants with depression, anxiety and stress were 4.5%, 8.8% and 5.7% respectively. Following a healthful eating plan (p<0.001) was found to be significantly associated with anxiety; those with anxiety practised this activity in fewer days than those without anxiety. Generally, self-care activities were poorly practiced by the participants, except for taking diabetes medications. Thus, the patients should be encouraged to improve their self-care activities. Psychological problems were also found to be uncommon. However, anxiety symptoms should not be ignored as it may negatively affect their adherence to healthy diet.