<p>The blood-brain barrier (BBB) is a highly selective interface between the peripheral circulation and the central nervous system (CNS), crucial for maintaining brain homeostasis. Disruptions to the BBB, such as increased permeability or structural damage, can lead to neurological damage. Mitochondria, the primary energy producers within endothelial cells, play a key role in the function of the BBB by maintaining its integrity and low permeability. This review first outlines the structural components of the BBB, then examines the role of mitochondria in endothelial cells under physiological conditions. We further focus on alterations in mitochondrial function during pathological states, discussing their impact on BBB stability. Briefly, this review explores the involvement of mitochondria in BBB endothelial cells in both physiological processes and the pathological progression of neurological diseases, while proposing potential therapeutic directions for treating CNS disorders. </p>