This work aimed to investigate the effect of bromocriptine on the blood sugar level in mice. Results indicate that bromocriptine (2.4 and 6 mg/kg I.P.) produces a significant hyperglycaemic effect which was counteracted by tolbutamide (150 mg/kg I.P.) or by sulpiride (10 mg/kg I.P.). Since sulpiride is a selective D-2 dopaminergic blocker, it is suggested that bromocriptine exerts its hyperglycaemia effect through stimulation of D-2 dopaminergic receptors. As bromocriptine decreases serum insulin activity in rats and inhibits insulin release of isolated mouse pancreatic islets, the bromocriptine-induced hyperglycaemic effect might be attributed, at least partially, to its effect on insulin release.