Carnitine, endogenously derived from the amino acids lysine and methionine in the body and exogenously derived especially from animal sources in the diet, is a vitamin-like amino acid derivative. Carnitine is an important molecule involved in the beta oxidation of fatty acids, that is energy metabolism, regulation of ketogenesis and removal of toxic components from the body. However, in patients undergoing hemodialysis treatment, many factors, such as the fact that carnitine is a highly dialysable molecule and the restriction of endogenous synthesis caused by damage to the kidneys, lead to the formation of secondary carnitine deficiency. Prevention of carnitine deficiency in hemodialysis patients is important for improving many of the symptoms and complications associated with hemodialysis. The purpose of this review was to examine the beneficial effects of L-carnitine use on hemodialysis-related symptoms and complications in hemodialysis patients.