Hepatocellular carcinoma (HCC) is the primary cancer of the liver. The present study aimed to assess the potential role of the endogenous regulators of angiogenesis like neurotransmitters, as possible HCC biomarkers. Five groups of rats were used in this study (8 rats per each): control healthy group (I), four intoxicated groups (II, III, IV, and V) used for induction of HCC with a single IP dose of diethylnitrosamine (DENA), 200 mg/kg. Groups II, III, IV, and V were sacrificed after 8, 16, 24, and 32 weeks of DENA injection respectively. Serum levels of epinephrine, nor-epinephrine, serotonin, and dopamine of all animals were estimated using high performance liquid chromatography technique coupled with fluorescence detector (HPLC-FLD). Development of HCC was confirmed histopathologically. Our results showed a significant increase in 3 neurotransmitters (epinephrine, nor-epinephrine, and serotonin) in DENA intoxicated HCC rat model. Only serotonin exhibited a significant increase in early histological stage HCC development (16 weeks post DENA injection) in comparison to alpha-fetoprotein (AFP), (24 weeks post DENA injection). These results suggest that neurotransmitters (Epinephrine and Norepinephrine) may have a role as a biomarker for late histological stage HCC. Like AFP, while serotonin may be used for early stage HCC.