OBJECTIVES: To characterize factors contributing to physical resilience in older cancer survivors, as demonstrated by resistance to decline or recovery (resilience). MATERIALS AND METHODS: We conducted a secondary analysis of data from a randomized controlled trial of cancer survivors ≥65years old and ≥5years from cancer diagnoses. Physical function was assessed quarterly over 2years, with Short-Form 36 physical function subscale. Participants with ≥2 follow-up assessments (n=594) were evaluated for physical resilience: 1) Resistance was defined as lack of any decline, where decline was a drop of ≥13 points, and 2) resilience (i.e., recovery) was defined as regaining ≥50% of lost function, subsequent to decline. RESULTS: Mean age was 73.1years and 89.1% were Caucasian. Forty-nine percent (n=289) were resistant to decline in function; these individuals were younger, had higher education and income, were more likely to be Caucasian, and had higher baseline physical function (mean difference [MD] 7.8 points, 95% CI 5.0-10.8) and general health (MD 7.5 points, 95% CI 4.9-10.1). Fifty-seven percent (n=137 of 239) demonstrated resilience, with 91.2% (n=125) recovering within 6months of declines; these participants had higher baseline physical function (MD 6.6 points, 95% CI 1.8-11.4), but similar pre-decline function. More participants who were resistant, and more who showed resilience, reported high self-efficacy and social support. CONCLUSIONS: The majority of older cancer survivors exhibited physical resilience; this was associated with high baseline health, physical function, self-efficacy, and social support. Assessing and targeting psychosocial factors may be important for interventions seeking to promote physical resilience.