There have been no studies on the characteristics of parenteral nutrition (PN) supply for adult inpatients in South Korea. The aim of this retrospective multicenter cross sectional study was to investigate the current practice and characteristics of PN support in hospitalized adult patients in South Korea for the first time. This study was conducted retrospectively for the adult patients who were hospitalized and received PN in nine hospitals on August 1st, 2017 to October 30th, 2017. We evaluated the type of PN formulation, PN administration period, administration route, calories supplied, amount of protein supplied, and laboratory results. Among the 11,580 inpatient admissions on that day, 1,439 patients received PN (12.4%). The majority of enrolled patients (96.5%) used the commercial PN, of which 86.2% were multi-chamber. 71.2% of them received PN peripherally. The average in hospital PN duration was 17.8 ± 52.6 days. Patients received only 65.4 ± 25.4% calories of their target calories. The in-hospital mortality of enrolled patients was 22%. In South Korea, commercial PN was usually administered to hospitalized adult patients and in-hospital mortality in adult patients using PN was higher in South Korea compared to other countries. This study provides the characteristics and the PN support status of hospitalized adult patients receiving PN in South Korea.