Abstract Background and Aims Sarcopenia is defined as a chronic condition of “muscle failure”, characterized by reduced muscular strength, mass and performance. End-stage renal disease (ESRD) and sarcopenia have several complications in common including inflammation, low sexual hormones, reduced levels of Vitamin D, and low satellite cells proliferation rate. Sarcopenic and uremic patients have higher risk for fracture, cardiovascular events, cognitive impairment, low quality of life, hospitalization and death. The European Working Group on Sarcopenia in Older People (EWGSOP2) 2019 guidelines standardize the diagnostic criteria and recommend a systematic approach for sarcopenia assessment. The aim of our study is to evaluate the prevalence of sarcopenia in ESRD patients not yet on dialysis and to characterize their clinical, laboratory and behavioral features. Method This is a pilot cross-sectional study. ESRD patients expected to initiate replacement therapy (hemodialysis or peritoneal dialysis), age ≥60 years, free mobility and hemoglobin levels ≥9.5 g/dL were enrolled. Exclusion criteria were: use of steroids >3 months during the previous year, previous renal replacement treatments. Enrolled patients were screened for sarcopenia following the three diagnostic criteria: muscle strength (through “handgrip strength” and “chair stand-up test”), muscle mass (with dual X-ray absorptiometry and bio-electrical impedance analysis), and muscle performance (with “4m gait speed test”). Clinical data were collected as well as anthropometric measures. Patients also underwent an abdominal ultrasound and a hematology, chemistry, urinary and inflammation laboratory panel. Finally, they filled questionnaires for sarcopenia identification (SARC-F), quality of life (SF-36), daily activity (ADL and iADL) and nutritional status. GFR was estimated according to CKD-EPI formula. Results We evaluated 9 patients (2 females and 7 males), mean age 72 ± 7 years, mean GFR 10.2±1.5 mL/min/1.73 m2 (range 7.3, 11.8). 7/9 reported hypertension history, 4/9 were diabetic. The prevalence of sarcopenia was 44% (4 patients) according EWGSOP2 criteria. Table 1 reports diagnostic exam results from our cohort. Taking individually EGWSOP2 criteria 4 patients showed low muscle strength, 5 reached the threshold for a low DXA muscle mass while 3 patients had a low gait speed performance, marker for sarcopenia severity. Compared with controls, sarcopenic patients (Table 2) showed a significantly lower handgrip strength (15.0±4.3 vs 23.0±6.7 Kg respectively, p-value 0.03), a lower but not significant appendicular lean mass (ALM) index normalized for squared height (European criteria) or for BMI (American criteria). Moreover, sarcopenic patients were more anemic (p 0.05), with a lower hematocrit (p 0.04). Finally, SF36 questionnaire describes sarcopenic patients as more jaded about physical activity, with impaired social activity and higher bodily pain. Conclusion Sarcopenia has a complex and diversified background, and ESRD represents an important risk factor. Sarcopenic patients with ESRD might need more carefulness on daily activity, anemia management, physical functioning and muscle recovery.