Background Splenic infarction is a frequently missed diagnosis in acute clinical conditions and is often under-diagnosed due to the lack of high-quality evidence on pathophysiology of splenic infarction. Due to the scarcity of such evidence, no consensus guidelines regarding the diagnostic approach and management of patients with splenic infarction exist. Most of published articles on splenic infarction are case reports and there was no systematic review on splenic infarction. Methods We conducted a retrospective analysis of all radiologically confirmed cases of splenic infarction patients with any history of admission at National Center for Global Health and Medicine Kohnodai Hospital, from 2014 to 2020. Further, to understand the pathophysiology that causes splenic infarction, we searched the literatures on splenic infarction. Results We found 18 patients with splenic infarction. The average age was 78 years, and about half of patients had abdominal pain; however, the other half did not have abdominal pain. One-third of patients with splenic infarction died. Leukocytosis with neutrophilia, a decrease of lymphocytes, anemia, hypoalbuminemia, and liver dysfunction were observed. Fibrinogen was decreased and D-dimer was remarkably elevated. Lactate dehydrogenase (LDH) and C-reactive protein (CRP) were remarkably increased. Six patients (33.3%) had cancer, four patients (22.2%) had atrial fibrillation, and four patients (22.2%) had infection. We found 466 case reports on splenic infarction published from 1975 to 2021. Recently, the number of case reports on splenic infarction due to infection, especially, coronavirus disease 2019 (COVID-19), has been remarkably increasing. Furthermore, we found that leukocytosis, a decrease of lymphocytes, elongated activated partial thromboplastin time, decrease of fibrinogen, liver dysfunction, elevation of LDH and blood urea nitrogen can be the prognosis predicting factors for patients with splenic infarction. Conclusion Our study elucidated clinical, hematological, biochemical and radiological characteristics for patients with splenic infarction. We newly found significant differences in blood cell counts, coagulation markers, transaminases, LDH and blood urea nitrogen between patients who died and those who survived, suggesting that these parameters can be the prognosis predicting factors for splenic infarction. Further, our systematic review on case reports about splenic infarction showed the etiology of splenic infarction and the trend of the causative diseases.