Introduction: Aim of this study was identify the prevalence of frailty in patients with idiopathic Parkinson’s disease (PD), to describe the relationship between severity of the disease and frailty, and to evaluate if timed up and go (TUG) is an eligible test for determination of frailty in idiopathic PD patients. Methods: We conducted a cross-sectional study which included 66 patients, aged 60 and over in a tertiary hospital. Frailty was assessed by the Fried Frailty Index (FFI). Severity of the idiopathic PD was detected by the Hoehn and Yahr (H&Y) scale. Mobility was measured by the TUG test. Demographic characteristics and comprehensive geriatric assessments were evaluated. Descriptive statistics and logistic regression were used in analyses. Receiver operating characteristic (ROC) curves were used to identify the discriminative effect of TUG test on frailty. Results: The numbers of frail, prefrail, and robust subjects were 34 (51.5%), 24 (36.4%), and 8 (12.1%), respectively. Dependency in instrumental activities of daily living (IADL) was significantly associated with frailty (Odds ratio (OR): 36.00, Confidence interval (CI): 8.43–153.80). Multivariate logistic regression analysis results yielded, depression (OR: 10.37, CI: 2.82–38.12) and higher levodopa doses (OR: 6.28, CI: 1.77– 22.24) were independently associated with frailty. TUG test performance was strongly associated with frailty with high sensitivity (0.806) and specificity (0.826) (Area under the curve (AUC): 0.831). Conclusions: Frailty is highly prevalent in idiopathic PD and is strongly associated with disabilities as well as specific risk factors of the disease. The TUG may be a reliable test for prediction of frailty in patients with idiopathic PD.