Background: Non-alcoholic fatty liver disease (NAFLD) is considered to be the liver component of the metabolic syndrome and is frequently associated with obe sity, dyslipidemia and type II diabetes mellitus (NIDDM).We aimed to determine t he development of liver function tests (LFTs) and metabolic complications in pat ients previously diagnosed with NAFLD. Methods: One-hundred-and-two patients with NAFLD diagnosed in the period 1994-2001 were identified. Eighty were broug ht in for new investigations, including LFTs, blood pressure, BMI, lipid profile , blood glucose and insulin. Original liver biopsy was re-evaluated. Results: S ixty-two patients (77%) were males (median age 46 years; mean follow-up time 2.8 ±1.2 years). Fifty-four patients (68%) were light to moderately overweigh t with body mass index (BMI) 25-30 kg/m 2. Mean BMI (28.2) was the same at diag nosis and at follow-up (28.3). At the new examination, 18 patients (23%) had d eveloped diabetes mellitus type II (n = 6) or had impaired fasting glucose (IFG) (n = 12), compared to only 2 patients at diagnosis. Hyperinsulinemia was observ ed in 19 patients (24%). Dyslipidemia, with elevated triglycerides and/or hyper cholesterolemia, was now present in 65 patients (81%). Twenty-two patients (27 %) had hypertension compared to 9 (11%) at diagnosis. Liver biopsy was perform ed in 24%, and 89%of those fulfilled the criteria for NAFLD. However,mild infl ammation and fibrosis was observed, grade 1-2 (n = 17), stage I-II (n = 13) an d none had cirrhosis. Conclusion: A significant proportion of patients with both clinical and histological diagnosis of NAFLD develop metabolic problems soon af ter diagnosis. These patients should be screened regularly for metabolic disorde rs. Background: Non-alcoholic fatty liver disease (NAFLD) is considered to be the liver component of the metabolic syndrome and is frequently associated with obesity, dyslipidemia and type II diabetes mellitus (NIDDM) .We aimed to determine he development of liver function tests (LFTs) and metabolic complications in pat ients previously diagnosed with NAFLD. Methods: One-hundred-and-two patients with NAFLD diagnosed in the period 1994-2001 were identified. Eighty were broug ht in for new investigations, including LFTs, blood Results: Sixty-two patients (77%) were males (median age 46 years; mean follow-up time 2.8 ± 1.2 years). Fifty-four patients (68%) were light to moderately overweigh t with body mass index (BMI) 25-30 kg / m 2 Mean BMI (28.2) was the same at diag nosis and at follow-up (28.3) the new examination, 18 patients (23%) had d eveloped diabetes mellitus type II (n = 6) or h Hyperinsulinemia was observ ed in 19 patients (24%). Dyslipidemia, with elevated triglycerides and / or hyper cholesterolemia, was now present in 65 patients (n = 12), compared to only 2 patients at diagnosis (81%). Twenty-two patients (27%) had hypertension compared to 9 (11%) at diagnosis. Liver biopsy was performed ed in 24%, and 89% of those fulfilled the criteria for NAFLD. However, mild infl ammation Stage 1-II (n = 13) an d none had cirrhosis. Conclusion: A significant proportion of patients with both clinical and histological diagnosis of NAFLD develop metabolic problems soon af ter diagnosis. These patients should be screened regularly for metabolic disorde rs.