Background rnAssessment of injection device use and injection technique, are key components of arncomprehensive diabetes medical evaluation and treatment plan. Proper insulin injection technique rnmay lead to more effective use of this therapy and, as such, holds the potential for improved clinica lrnoutcomes. The lack of a clear number of patients with diabetes mellitus requiring insulin therapy,rnand few studies focused on either assessing injection techniques or associated complicat ions rnseparately have indicated suboptimal knowledge and skill with higher than the worldwide averagernon the presence of complications. rnObjective rnMajor insulin injection parameters were assessed among patients with diabetes mellitus on followuprnrnat the adult diabetes referral clinic in TASH, Addis Ababa from September 1 to October 31, rn2020. rnMethods rnA cross-sectional survey was conducted from September 1 to October 31, 2020, at the diabetesrnclinic in Tikur Anbessa Specialized Hospital. Data were collected by using a structured, rninterviewer-administered questionnaire. Then, entered and analyzed using SPSS version 20. To rnidentify factors associated with injection techniques, bivariable and multivariable binary logist icrnregression analyses were done. Statistical significance was considered at a level of significance of rn5%, and adjusted odds ratio (AOR) with 95% confidence interval (CI) was used to present thernestimates of the strength of the association rnResults rnA total of 293 participants were included in this study. The most common type of diabetes reportedrnwas Type 2 diabetes mellitus. From the recommended injection sites, 256 (87.4%) inject at more rnthan 1 site with the thigh (249/85%) being the most often used site. The median total daily insulinrndose was 54IU. Insulin syringe reuse was practiced by practically all (98%) of the participants.rnInjection site rotation is practiced by 272 (92.8%) of the participants. The presence of anyswellings or lumps over the injection sites was reported by 113 (38.6%) of the participants withrnthe thigh being the most common site. Disposal of used syringes capped into the trash is the rnpractice of 176 (60.1%) of the study participants. From the multivariate analysis, sex (AOR=2.33,rn95% CI:1.13-4.83), total daily dose of insulin (AOR=0.99, 95% CI:0.98-0.99), last time injection rninstructions were reviewed (AOR=0.35, 95% CI:0.13-0.97) and hyperglycemia eventsrn(AOR=0.56, 95% CI:0.31-0.99) showed significant association with the presence ofrnlipohypertrophy. rnConclusion: This study revealed that there are alarmingly high rates of injection-relatedrncomplications. The diabetes education given pertaining to injection parameters and evaluation of rninjection sites are neglected which will fuel the occurrence of complications. It highlights the needrnfor the provision of patient-centered instruction and education about insulin injection techniques.