||The purpose of this study was to determine the association of each of five cardiometabolic risk factors (diabetes, hypertension, elevated triglycerides, low high density lipoproteins, obesity), and MetS (three or more risk factors present) with the level of physical function 1) prior to surgery in patients with TKA/THA surgery and 2) 6 weeks postsurgery in patients with TKA/THA surgery, controlling for age, sex, physical activity, and comorbidity. Patient physical function data were retrospectively extracted from a clinical orthopedic database between September of 2008 and November of 2010. Comorbidities were obtained by chart abstraction. Patients were ≥40 years old with a primary total hip or knee arthroplasty. Relationships between MetS and its individual components, and physical function were completed using the Lower Extremity Function Scale (LEFS) and SF-36 physical component score (PCS). Covariates were age, sex, comorbidities, and physical activity. Preoperatively, a total of 174 TKA and 112 THA candidates were included. For TKA candidates, mean LEFS scores were significantly (p<0.001) lower for patients with MetS (30.0, SD 14.2) than without MetS (39.9, SD 16.0). In TKA cohort, MetS remained significantly associated with reduced lower-extremity physical function; additionally, female sex, chronic back pain and insomnia significantly reduced preoperative lower-extremity physical function, in the adjusted analysis. For THA iv candidates, adjusted analysis found MetS and being female were significantly (p<0.05) associated with worse lower-extremity physical function. Postoperatively, 170 and 111 patients with a total knee and total hip arthroplasty were included. In the adjusted analysis: Diabetes, chronic back pain and presurgical physical function remained significantly associated with reduced postoperative lowerextremity physical function. For THA, being female, chronic back pain and presurgical physical function were significantly (p<0.05) associated with worse physical health. MetS was not significantly associated with postoperative physical function (PCS or LEFS) in the THA/TKA population. This study provides evidence that MetS, back pain, and insomnia are modifiable conditions that influence preoperative physical function while back pain, diabetes and preoperative physical function are modifiable conditions that influence postoperative physical function. MetS was not associated with postoperative physical function in either the TKA or THA cohort.