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Introduction. Sarcopenia is associated with significant morbidity and mortality in peritoneal dialysis (PD) patients. Three different tools need to be applied to measure the three diagnostic indices of sarcopenia. Given the cumbersome diagnostic steps and multi-layered mechanisms underlying sarcopenia, we combined a new biomarker with bioelectrical impedance analysis (BIA) data to predict PD sarcopenia. Methods. Patients undergoing regular PD were invited to complete screening for sarcopenia, including limb skeletal muscle quality, grip strength, and the chair standing time test on five occasions, in accordance with the newly revised diagnostic consensus of the Asian Working Group for Sarcopenia (AWGS2019). Serum was collected for centralized detection of irisin levels. BIA data, especially the phase angle (PhA), as well as the patient’s general clinical information, dialysis related indices, laboratory data, and body composition data were recorded. Results. Among the 105 enrolled PD patients (41.0% male, mean age 54.2 ± 8.89 years), the prevalence of sarcopenia was 31.4% and sarcopenic obesity 8.6%. Binary regression analysis showed that serum irisin concentrations (OR = 0.98; 95% CI: 0.97-0.99; p = 0.002), PhA (OR = 0.43; 95% CI: 0.21-0.90; p = 0.025) and body mass index (BMI) (OR = 0.64; 95% CI: 0.49-0.83; p = 0.001) were independently associated with DP sarcopenia. The AUC of the combined use of serum irisin concentrations and PhA to predict sarcopenia was 0.925 with 100% sensitivity and 84.0% specificity in men, and was 0.880 with 92.0% sensitivity and 81.5% specificity in women. The DP sarcopenia score was = 1,533.48 + -0.75 * Grip strength + 4.63 * BMI + -18.07 * Total body water + -11.87 * Extracellular water/total body water + 9,26 * Fat-free mass index + -83.41 * PhA + 22.42 * Albumin/Globulin + -26.38 * Blood phosphorus + -17.04 * Total cholesterol + -29.02 * Triglycerides + -0.29 * Prealbumin + -0.17 * Irisin. Conclusion. Sarcopenia is relatively common in PD patients. The combination of serum irisin and PhA concentrations facilitated rapid prediction of DP sarcopenia and could serve as an optimal screening tool for DP sarcopenia in the clinical setting.