The Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine is the first novel nucleoside-modified messenger ribonucleic acid (modRNA) vaccine to receive Emergency Use Authorization from the Food and Drug Administration in the United States. It is indicated to be used in patients ≥12 years-of-age as of May 25th, 2021, including populations with high atherosclerotic cardiovascular disease (ASCVD) burden. However, little is known about the potential impact this vaccine may have on serum lipoprotein levels in patients with familial hypercholesteremia (FH), who are predisposed to high ASCVD burden due to elevated low-density lipoprotein cholesterol (LDL-C). We present an interesting case where a patient with heterozygous FH (HeFH) and elevated triglycerides (TG)-controlled for years on medication and apheresis-experienced significantly elevated TG, one day after receiving his second Pfizer-BioNTech COVID-19 vaccine dose. It is not known whether this adverse event may be seen in other FH patients and may be worth assessing in such patients to determine the possibility of a rare adverse reaction from a COVID-19 vaccine.