MOSAIc is a 2-year prospective cohort study of patients with type 2 diabetes taking insulin in 18 countries. We investigated how aspects of the patient-physician relationship were associated with insulin treatment progression, insulin adherence, and HbA1c levels. Patients were ≥18 years and taking insulin for ≥3 months with/without other antidiabetic medications. Clinical, demographic, and psychosocial data were collected at baseline and during follow-up. Multiple imputation via chained equations was used for missing data. Multivariable linear or logistic regression models examined the effect of baseline Interpersonal Process of Care (IPC) subscale scores on the a) Diabetes Distress Scale (DDS), b) Diabetes Knowledge Test (DKT), c) self-monitoring blood glucose (SMBG), d) adherence (missed injections in the last week), e) insulin treatment progression (increase in antidiabetic treatment complexity), and f) Year-2 HbA1c level. We adjusted for demographic characteristics, socioeconomic status, and baseline DDS, DKT, SMBG, insulin adherence, and HbA1c levels. Among 2706 patients included, mean±SD age was 62.1±10.8 years, 50.0% were women, and mean±SD HbA1c was 8.1%±1.9 at baseline. Among the IPC domains, hurried communication was significantly associated with higher DDS (β=0.12; 95% CI: 0.04, 0.20; p<.01) at Year 2. Elicited concerns (β=–0.18; 95% CI: –0.28, –0.07; p<.01) and discriminated style (β=–0.15; 95% CI: –0.28, –0.03; p=.02) were significantly associated with lower HbA1c level at Year 2. IPC domains were not independently associated with DKT, SMBG, adherence, or insulin progression over 2 years. Findings suggest that key aspects of patient-physician communication may influence diabetes-related emotional distress and glycemic control over time.