Background: Therapeutic decision-making in older patients with cancer is challenging, and there is a need for a clinical parameter that can guide these decisions. The Timed Up and Go (TUG) test is an easy-to-administer tool that measures physical performance and may help to identify vulnerable patients.Objectives: We aimed to study the association between the TUG and overall survival in older Indian patients with cancer. We also aimed to evaluate the factors that were associated with a poor TUG score, to define the optimal cut-off score for older patients with cancer, along with the sensitivity and specificity.Materials and Methods: This prospective observational study was conducted in the geriatric oncology clinic at the Tata Memorial Hospital, a tertiary care center in Mumbai, India, between June 2018 and January 2022. We included adults aged 60 years and above, who had a diagnosis of malignancy, and had undergone a multidimensional geriatric assessment. Patients without a TUG score and for whom survival information was not available were excluded. Using the Short Physical Performance Battery (SPPB) as the gold standard, Receiver Operating Characteristic (ROC) curves with Area Under the Curve (AUC) were used, and the cut-off score with optimum sensitivity and specificity was derived. Mean values between two and more groups were compared using t test and analysis of variance, respectively. Categorical variables were compared using Fisher's exact and Pearson's Chi-squared test. The Kaplan–Meier survival estimate, and the unadjusted and adjusted Cox proportional-hazards model were used for survival analysis.Results: We enrolled 851 patients in the study. The median age was 69 (IQR, 65 to 73) years; 544 patients (76%) were men. We found that the TUG in women (median TUG, 11 seconds; IQR, 9.5 - 13.7) was longer than in men (median TUG, 9.6 seconds; IQR, 8.2 -11.6); P < 0.01. The TUG score increased significantly with increasing age in both sexes. Presence of comorbidities impaired cognition, poor nutritional status, depression, and anxiety were significantly associated with higher TUG scores. TUG was a significant predictor of mortality on both the univariate (HR, 1.056; 95% CI, 1.037–1.075) and multivariate models (HR, 1.058; 95% CI, 1.039–1.078). The median survival of patients with TUG <12 seconds was 13.9 months (95% CI, 11.2 to 16.5), compared to 8.5 months (95% CI, 6.6 to 10.3) in those with a TUG ≥ 12 seconds (P = 0.002). The TUG cut-off score of 10 seconds had an AUC-ROC, sensitivity of 62.32% and specificity of 80.58%.Conclusion: TUG can be a reliable tool in a busy outpatient setting to identify vulnerable patients who require a detailed geriatric assessment. A TUG score of ≥ 10 seconds is a good predictor of impaired mobility. Further 0.78 interventional studies are required to identify the benefits of physical therapy in older patients with cancer.