Objective This study aimed to examine the association between performance of self-care activities and patient or disease factors as well as patient activation levels in patients with diabetes and chronic kidney disease ( CKD) in Australia. Methods A cross-sectional study was conducted among adults with diabetes and CKD ( eGFR <60 mL/min/1.73m2) who were recruited from renal and diabetes clinics of four tertiary hospitals in Australia. Demographic and clinical data were collected, as well as responses to the Patient Activation Measure ( PAM) and the Summary of Diabetes Self-Care Activities ( SDSCA) scale. Regression analyses were performed to determine the relationship between activation and performance of self-care activities. Results A total of 317 patients (70% men) with a mean age of 66.9 ( SD=11.0) years participated. The mean ( SD) PAM and composite SDSCA scores were 57.6 (15.5) % (range 0-100) and 37.3 (11.2) (range 0-70), respectively. Younger age, being male, advanced stages of CKD and shorter duration of diabetes were associated with lower scores in one or more self-care components. Patient activation was positively associated with the composite SDSCA score, and in particular the domains of general diet and blood sugar checking ( P<.05), but not specific diet, exercising and foot checking. Conclusion In people with diabetes and CKD, a high level of patient activation was positively associated with a higher overall level of self-care. Our results identify subgroups of people who may benefit from tailored interventions to further improve their health outcomes. Further prospective studies are warranted to confirm present findings.