Background/Aim: Hepatocellular carcinoma (HCC) is a particularly malignant form of cancer prevalent throughout the world; however, there is a pressing need for HCC biomarkers to facilitate prognosis and risk assessment. Patients and Methods: This paper reports on the potential prognostic value of WNK lysine deficient protein kinase 1 (WNK1) in cases of HCC. We analyzed the expression of WNK1 at the mRNA level using omics data from the UALCAN database. We then verified our findings through the immunohistochemical (IHC) staining of various human cancer tissue as well as 59 HCC samples paired with corresponding normal tissues. The prognostic value of mRNA or protein expression by WNK1 was evaluated using the Kaplan-Meier method. Results: Initial screening results revealed significantly higher WNK1 expression levels in HCC tissue compared to normal tissue. Verification using the paired HCC samples confirmed that the expression of WNK1 was indeed significantly higher in HCC tissue samples than in adjacent normal tissues. High WNK1 expression levels were significantly correlated with clinicopathological variables, including gender and histologic grade. Kaplan-Meier survival analysis revealed that high WNK1 expression levels were associated with poor HCC prognosis. Finally, univariate and multivariate analysis identified WNK1 as a prognostic factor for TNM stage in cases of HCC. Conclusion: In summary, WNK1 is overexpressed at the mRNA and protein levels, and correlated with poor prognosis. Thus, WNK1 expression could potentially be used as a biomarker in HCC prognosis. Hepatocellular carcinoma (HCC) is responsible for an enormous number of cancer-related deaths, particularly in sub-Saharan Africa and Southeast Asia (1, 2). HCC is among the deadliest forms of cancer, and the treatment of HCC has been well demonstrated in multiple series, with an overall 5year survival rate between 33% and 55% (3). The most common risk factors include infections with hepatitis B virus (HBV) or hepatitis C virus (HCV), chronic exposure to aflatoxin B (AFB1), excessive alcohol consumption (EAC), non-alcoholic steatohepatitis (NASH), and metabolic syndrome (METS). HCC commonly progresses from chronic liver inflammation and cirrhosis, which eventually trigger the formation of liver tumors (4, 5). The fact that the early symptoms of HCC are not obvious means that at the time of diagnosis, most patients are in the middle or late stages of the disease (i.e., beyond the window for surgery). Note that 50% of patients who undergo radical surgical 2631 This article is freely accessible online.