PCSK-9 has a tremendous role in lipid metabolism. PCSK9 variants have been concomitantly linked to alterations in plasma lipid profile, leading to increased risk of cardiovascular disease and diabetes mellitus. The aim of our study was to determine the frequency of PCSK-9 I474V variant in hypercholesterolemic and diabetic subjects. Plasma lipid profile and fasting blood glucose were assayed in 30 healthy, 25 hypercholesterolemic, and 45 diabetic subjects. Genomic DNA was extracted from whole blood and PCR was run using specific primers to obtain an amplicon harbouring exon 9. The amplicon was later subjected to Sanger sequencing and. A missense mutation of PCSK9 I474V SNP was detected in the exon 9 of PCSK9 gene. Our results show a frequency of the PCSK9 I474V SNP in Hail region of Saudi Arabia and this frequency is higher among hypercholesterolemic and diabetic patients. To our best knowledge, this is the first report of mutation of this nature in Hail region of Saudi Arabia.