Background: Potent antiretroviral treatment has resulted in near normal life expectancy for people living with HIV. Consequently, there is an increased focus on comorbidities, frailty and quality of life. Methods: We assessed and compared the prevalence of frailty, associated factors and relationship with quality of life in older Australian men living with HIV in a cross-sectional study using three frailty measurements. The Frailty Phenotype, Frailty Index and Edmonton Frail Scale were applied to 93 HIV-infected men aged over 50 years, on antiretroviral therapy. Multivariable ordinal logistic regression was used to analyse the associations of frailty with covariates and quality of life. Results: The prevalence of frailty was 10.8% (n=10) using the Frailty Phenotype; 22.6% (n=21) using the Frailty Index and 15.1% (n=14) using the Edmonton Frail Scale. Frailty Phenotype-defined pre-frailty/frailty was associated with pre-1996 ART initiation (OR, 3.56; CI, 1.23, 10.36; P=0.020) and depression (OR, 3.74; CI, 1.24, 11.27; P=0.019). Osteoporosis, serious non-AIDS events and AIDS were associated with Frailty Index-defined frailty (OR, 4.84, CI, 1.27, 18.43, P=0.021; OR, 4.27, CI, 1.25, 14.58, P=0.020; OR, 4.62, CI, 1.30, 16.45, P=0.018, respectively) and Edmonton Frail Scale-defined frailty (OR, 7.51; CI, 1.55, 36.42; P=0.012; OR, 7.71; CI, 1.62, 36.75; P=0.010; OR, 8.53; CI, 1.70, 42.73; P=0.009, respectively), independent of age and current CD4+ T-cell count. Frailty, defined by any of the instruments, was significantly associated with poorer quality of life (P<0.001). Conclusions: Identifying frailty is an increasingly important contemporary consideration of HIV care related to ageing and quality of life.