COVID-19 vaccines are generally proven safe in all population and are highly recommended. However, rare adverse events have been reported. We hereby present a case of an 18-year-old man who presented to emergency department with fever, meningitis like symptoms, shortness of breath, chest pain, skin rash, and extreme fatigue. He had cardiac manifestations including hypotension, elevated troponin, and reduced ejection fraction. High inflammatory markers were also noted. He was initially worked up for and treated as a possible infectious etiology, but the microbiological studies were negative and there was no response to treatment. Since he had recently received booster dose of Pfizer-BioNTech COVID-19 vaccination three weeks prior to onset of symptoms, a possibility of Multisystem inflammatory syndrome in children (MIS-C) was made. His presentation fulfilled all the diagnostic criteria. The possibility for MIS-C being related to vaccination was proposed after relevant serological tests showed that the antibodies, he had were due to COVID-19 vaccine, not to a prior infection. After he received appropriate immunomodulatory treatment (IVIG and methylprednisolone) as per the guideline, he showed marked clinical improvement. Our case report highlights the need to consider MIS-C as a potential differential in young patients who present with unexplained multisystem illness with increased inflammatory markers and negative microbiologic work-up. MIS-C can be secondary to COVID-19 vaccination as well as to prior COVID-19 infection.