The purpose of this study was to assess the ability to self-inject insulin in elderly diabetes by clock drawing test. A descriptive cross-sectional study included over 60 year - old elderly type 2 diabetes, diagnosed according to ADA criteria 2012. The results showed that the mean age was 69.3 +/- 6.3, males/females ~ 0.7. The average duration of diabetes was 6.3 +/- 5.4. The percentage of patients with good, minor error and poor ability of self - injection was 34.4 percent, 40 percent and 25.6 percent. The rates of patients with spatial and/or planning deficit and conceptual deficit were 34.4 percent and 1.6 percent, respectively. There was a positive relationship between the ability of insulin self - injection and ability to do clock drawing test and MMSE score (p 0.05). Patients with spatial and/or planning deficit and conceptual deficit on clock drawing test were less able to perform insulin self - injection than patients without spatial and/or planning deficit and conceptual deficit (p 0.05). In summary, the clock drawing test should be performed to assess insulin self - Injection in elderly diabetic patients in order to guide appropriate insulin injection.