This pilot case study describes the isolation and partial purification of the Procollagen-lysine 5-dioxygenase (PLOD) enzyme from the blood serum of a single 42-year-old male patient diagnosed with coronary artery disease using different techniques, starting with precipitation with ammonium sulfate, dialysis and ion exchange technique. The results showed the presence of two peaks for protein solution; the first peak I showed the highest activity of the enzyme in (18.33 U/ml) band (A), with the specific activity (4.47 U/mg), and the highest activity for peak II was in (6.7 U/ml) band (B). A single band was obtained when applying electrophoresis to the enzyme purified by ion exchange that was used for estimating the molecular weight of the PLOD enzyme, which is approximately equal to (85) kilodaltons.