In this study, we investigated the effects of severe hemolysis (hemoglobin [Hb] > 500 mg/dL) in blood specimens by classifying them into non-hemolysis, hemolysis (Hb ≤ 500 mg/dL), and severe hemolysis. Investigated items were total protein (TP), albumin (ALB), total bilirubin (T-Bil), direct bilirubin (D-Bil), aspartate transaminase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LD), alkaline phosphatase (ALP), gamma-glutamyl transferase (γ-GT), creatine kinase (CK), amylase (AMY), cholinesterase (ChE), blood urea nitrogen (BUN), creatinine (Cre), sodium (Na), potassium (K), chloride (Cl), calcium (Ca), uric acid (UA), triglycerides (TG), total cholesterol (T-Cho), high-density lipoprotein cholesterol (HDL-C), lowdensity lipoprotein cholesterol (LDL-C), and C-reactive protein (CRP), and actual clinical test results were used. Based on the results, we were able to classify the error relationships into three groups according to hemolysis status. Group A shows an error between non-hemolysis and hemolysis, and an even stronger error in severe hemolysis (T-Bil, AST, LD, Na, K, Ca, and UA). Group B showed no error between non-hemolysis and hemolysis, but errors in strong hemolysis (ALB, D-Bil, ALT, γ-GT, CK, AMY, TG, T-Cho, HDL-C, and LDL-C). Group C shows no errors in either hemolysis or strong hemolysis (TP, ALP, ChE, BUN, Cre, Cl, and CRP). Among these, the Group B classification was a new finding. In situations where the measurement of hemolyzed specimens is unavoidable, it is important that clinical laboratory technologists be aware of its impact and provide the results in a way that can be used in clinical practice.