To determine 'hypothetical willingness' to initiate insulin, and identify associated factors, among adults with type 2 diabetes (T2DM) in primary care for whom insulin is clinically indicated.Eligible participants were adults with T2DM with an HbA1c ≥7.5% (58mmol/mol) and prescribed maximum oral hypoglycaemic agents. A total of 261 participants were recruited from 74 Victorian general practices: mean age 62±10 years; 39% (n=103) women; diabetes duration 10±6 years; HbA1c 9.0±1.3% (75±14mmol/mol). Data collected by the Stepping Up Study: demographic and clinical characteristics, 'willingness' to initiate insulin, insulin appraisals, depressive symptoms, and diabetes-related distress. A multinomial regression investigated predictors of 'willingness'.Nineteen percent (n=50) were 'very willing' to initiate insulin, if recommended. The final regression model (R(2)=.44, χ(2)(12) 145.91, p<.001) demonstrated higher socioeconomic status and less negative attitudes to insulin were associated with increased willingness to initiate insulin.Among adults with T2DM for whom insulin is clinically indicated, only one in five are 'very willing' to begin insulin therapy. Independent of demographics, clinical factors and emotional wellbeing, insulin appraisals were associated with 'willingness'. This study highlights the importance of addressing attitudinal barriers to insulin therapy among adults with T2DM in primary care to improve insulin receptiveness.