Hepatocellular carcinoma (HCC) has high morbidity and mortality rates, and metabolic reprogramming of HCC cells supports the proliferation and development of tumor cells. Lactate dehydrogenase (LDH), a key metabolic enzyme, can maintain the rapid proliferative demand of tumor cells by promoting glycolysis and lactate production in HCC cells. In addition, LDH regulates redox homeostasis and influences lipid synthesis and signaling pathways, further promoting tumor invasion and metastasis. In the tumor microenvironment, LDH affects the function of immune cells and stromal cells by regulating the lactate concentration in and promoting the immune escape and angiogenesis of tumor cells. Since elevated levels of LDH are closely associated with tumor load, invasiveness and poor prognosis, LDH also has promising applications in the early diagnosis, treatment and prognostic assessment of HCC. The present study reviewed the roles of LDH in the occurrence, development, diagnosis, prognosis and treatment of HCC and explored its value as an important biomarker and potential therapeutic target, with the aim of providing a comprehensive reference for HCC‑related research and clinical practice.