Kawasaki disease (KD) is characterized with an acute systemic vasculitis of the medium- and small-sized vessels. This disease mainly involves children within the age of 6 months to 5 years and it is often self-limited and patients seem to recover well; however, it may lead to devastating and fatal cardiovascular complications such as coronary artery aneurysm. Thus, early diagnosis and appropriate management of this disease have a significant effect on improving the prognosis and preventing its serious complications. Adult-onset KD (AKD) is rare and often misdiagnosed. Here we report a rare case of KD that occurred in a 17-year-old young adult who presented 4 weeks post splenectomy, with clinical signs and symptoms consistent with AKD. This may potentially highlight the association of AKD with infectious etiologies.