Patients with short bowel syndrome (SBS) are often depending on parenteral nutrition support (PNS), sometimes complicated by liver dysfunction. Phytosterols in parenteral lipid emulsions have been suspected to be responsible for cholestasis in paediatric nutrition support. The aim of the present study was to evaluate phytosterol intake and serum phytosterol levels in adult SBS patients. We quantified serum levels of phytosterols, cholesterol, and markers for bile acid and cholesterol synthesis, by gas or liquid chromatography in 21 healthy controls, and in 24 adult SBS-patients, 8 with and 16 without PNS. Phytosterols and cholesterol in parenteral lipid emulsions were also quantified. Serum levels in SBS-patients without PNS; with PNS; and in controls, were on average for phytosterols 11; 63; and 23 micromol/l (P<0.05 for differences), cholesterol 4,2; 3,8; and 5,1 mmol/l, lathosterol 808; 824; and 228 micromol/100 mmol cholesterol, and 7alpha-hydroxy-4-cholesten-3-one 207;191; and 18 nmol/l, respectively (P<0.05 between controls and SBS). Phytosterols in lipid emulsions ranged from 591 to 958 micromol/l. SBS-patients on PNS have higher serum levels of phytosterols than other SBS-patients and controls, possibly because of phytosterols in lipid emulsions. Patients with SBS, regardless of nutrition support, have lower serum levels of cholesterol but higher cholesterol and bile acid synthesis compared to controls.