The article reviews the dynamics of insulin granule release in pancreatic beta cells, focusing on the biphasic time course of glucose-induced insulin secretion. The first phase is rapid and transient, while the second phase is slowly developing and sustained. The release of insulin involves the packaging of insulin into small secretory granules, their trafficking to the plasma membrane, exocytosis, and retrieval by endocytosis. Recent advancements in techniques such as fluorescent protein labeling and real-time imaging have provided new insights into the pre-exocytotic and post-exocytotic processes. The article discusses the role of electrical activity, Ca²⁺ channels, and SNARE proteins in the exocytotic process, as well as the existence of distinct granule pools with different release competencies. It also explores the ultrastructural correlates of biphasic insulin secretion and the mechanisms underlying granule dynamics, including the role of the cytoskeleton and the significance of ATP and ADP in regulating exocytosis. The findings highlight the importance of understanding these mechanisms in the context of Type 2 diabetes, where defects in insulin secretion are observed.The article reviews the dynamics of insulin granule release in pancreatic beta cells, focusing on the biphasic time course of glucose-induced insulin secretion. The first phase is rapid and transient, while the second phase is slowly developing and sustained. The release of insulin involves the packaging of insulin into small secretory granules, their trafficking to the plasma membrane, exocytosis, and retrieval by endocytosis. Recent advancements in techniques such as fluorescent protein labeling and real-time imaging have provided new insights into the pre-exocytotic and post-exocytotic processes. The article discusses the role of electrical activity, Ca²⁺ channels, and SNARE proteins in the exocytotic process, as well as the existence of distinct granule pools with different release competencies. It also explores the ultrastructural correlates of biphasic insulin secretion and the mechanisms underlying granule dynamics, including the role of the cytoskeleton and the significance of ATP and ADP in regulating exocytosis. The findings highlight the importance of understanding these mechanisms in the context of Type 2 diabetes, where defects in insulin secretion are observed.