Background: Insulin is one of the most important anti-diabetic agents in the management of diabetes even among type 2 diabetic. Objective: There was need to assess insulin adherence, mode of insulin delivery and burden of insulin usage among diabetics. Methods: A cross-sectional, prospective questionnaire, orally administered at a Diabetes Clinic of a University Teaching Hospital, SouthWest, Nigeria. Participants were consecutive patients with diabetes who were 18 years or older presently on insulin either alone or in combination with other anti-diabetic agents for at least 3 months. Baseline demographic and insulin treatment information were obtained. Results: Two hundred and thirteen (213) participants were studied. Of these, 21 (9.9%) had T1DM and 192 (90.1%) had T2DM, (means age, 58.6 ± 13.1 years, mean duration of diabetes, 7.0 ± 6.9 years). Insulin adherence was noted in 72.8% with better adherence among those who self-injected insulin compared to those who were injected by health care professionals (HCPs) or relations. Among the respondents, 80.8% were on human insulin and pre-mixed insulin was the most commonly used form of insulin (52.6%). Most participants (52.6%) were taking 10-20 units per day, only 22 (10.3%) were on >40units/day. Reuse of insulin needle was found in 74.6% of the participants. Major reasons for insulin omission were non-availability of insulin and patients being tired of insulin injection. Conclusion: The insulin adherence among diabetics in this study was high. Non-availability of insulin, insulin injection pain and being tired of continual insulin usage were some of the reasons for non-adherent to insulin usage.