Non-insulin-dependent diabetes mellitus (NIDDM or Type II diabetes) is a multifactorial metabolic disorder in which hepatic glucose production is increased. Glycogenolysis and the main regulatory enzyme glycogen phosphorylase (GP) are responsible for the release of mono-glucose from poly-glucose (glycogen, as stored form in the liver). This protein possesses several binding pockets or cavities that regulate the catalytic functions of GP. So obviously, the inhibitors of GP will stop or slow down glycogenolysis as well as glucose production and ultimately the whole process will result in the recovery of diabetes in NIDDM patients. Glucose is one of most important regulators of GP, and glucose analog inhibitors (GAIs) have shown very promising activity for the inhibition of GP. There have been a large number of GAIs reported in last few decades that are promising for the control of NIDDM. This review briefly describes some aspects of GP and its relation with GAIs, mostly containing heterocyclic building blocks.