Objective: adipose tissue releases factors (adipokines) that influence local, peripheral as well as central processes. In the present study we determined the relationship between plasma concentration of a recently identified adipokine, pigment epithelium-derived factor (PEDF), and human obesity, particularly specific adipose tissue depots, and other features of the metabolic syndrome. Methods: we examined the plasma concentration of PEDF, anthropometric parameters, abdominal subcutaneous and visceral adipose tissue, lipid, glucose, insulin and alanine aminotransferase level in a non-diabetic general Caucasian population (n=59). Results: plasma PEDF level in males (6.2 +/- 2.1 mug/ml) was higher than in females (3.1 +/- 1.4 mug/ml; P<0.001). Plasma PEDF was positively correlated with age and all features of metabolic syndrome. However, in multiple linear regression analysis with adjustment for age and gender, only visceral fat thickness (beta=0.361, P=0.010) and body mass index (BMI) (beta=0.288, P =0.008) were significant independent determinants of plasma PEDF level, together with the gender (beta=-0.424, P<0.001). Conclusions: we conclude that the plasma PEDF level is strongly associated with body adiposity, in particular with the visceral fat depot in the non-diabetic general population. This association may (partly) explain the relationship between PEDF and metabolic syndrome in this population.