To identify insulin therapy appraisals among adults with Type 2 diabetes using insulin and how negative appraisals relate to clinical, self-care and psychosocial outcomes.Diabetes MILES - Australia 2011 was a national survey of adults with diabetes, focused on behavioural and psychosocial issues. Subgroup analyses were conducted on the responses of 273 adults with Type 2 diabetes using insulin (46% women; mean ± sd age: 59 ± 9 years; diabetes duration: 12 ± 7 years; years using insulin: 4 ± 4). They completed validated measures of insulin therapy appraisals (ITAS), depression (PHQ-9), anxiety (GAD-7), diabetes distress (PAID) and diabetes-specific self-efficacy (DES-SF).Insulin was perceived to be very important, and its benefits (e.g. improves health) were endorsed by most (82%). Fifty-one per cent believed that taking insulin means their diabetes has become worse; 51% that insulin causes weight gain; 39% that they have 'failed to manage' their diabetes. Those with the greatest and least 'ITAS negative' scores did not differ by diabetes duration or years using insulin, or by average number of insulin injections or blood glucose checks per day. Those with more negative insulin appraisals were significantly younger (Mean Diff. = 5 years, P < 0.001), less satisfied with recent blood glucose levels (P < 0.001, d = 0.63), had reduced diabetes-specific self-efficacy (P < 0.001, d = 0.7), and were more likely to report depressive symptoms, anxiety or diabetes distress (all P < 0.001, d = 0.65-1.1).Negative insulin therapy appraisals are common among adults with Type 2 diabetes using insulin, and are associated with lower general and diabetes-specific emotional well-being, reduced diabetes-specific self-efficacy and satisfaction with blood glucose.