Glucagon-Like Peptide-1 (GLP-1) receptor agonists, used as glucose-lowering drugs, also induce weight loss by inhibiting food intake. The present study was aimed at the assessment of the in vitro effects of the GLP-1 receptor agonist liraglutide on proliferation and differentiation of human adipose stem cells (ASC) obtained from subcutaneous adipose tissue of morbidly obese subjects undergoing bariatric surgery. Liraglutide (10-100 nM) significantly inhibited ASC proliferation and viability, with a maximum effect at 6 days of culture (45% and 50%, for liraglutide 10 and 100 nM, respectively); the effect was reverted by exendin 9-39. Glucose uptake was significantly reduced by liraglutide in a dose dependent manner. Treatment with liraglutide reduced intracellular lipid accumulation in differentiating ASC, together with FABP-4 mRNA expression (-18%, -23%, -46%, for 1 nM, 10 nM and 100 nM, respectively), whereas it stimulated adiponectin (APN) expression (1.86-, 2.64-, 2.28-fold increase, for 1 nM, 10 nM and 100 nM, respectively). Liraglutide exerts effects on human adipose cell precursors, inhibiting proliferation and differentiation, while stimulating the expression of the insulin-sensitizing adipokine APN. These effects could contribute to the actions of GLP-1 receptor agonists on body weight and insulin sensitivity.