Introduction: Inflammation promotes the progression of chronic renal failure, and the start of dialysis worsens inflammation. The enlargement of the spleen is associated with inflammation, and patients on hemodialysis may show a large spleen. The aim of the present study was to compare the spleen size of patients undergoing hemodialysis versus controls to update this thread. Methods: Controls and patients were eligible to participate in the study provided they were negative for serological markers of hepatitis B and C viruses and HIV, if they had no lymphoproliferative disorder, and if they were at least 18 years of age. Age, sex, and the duration of dialysis were recorded. Laboratory variables (hemoglobin, hematological cell count, serum creatinine) and the underlying cause of end-stage renal disease were analyzed. The spleen sizes of the patients were divided into tertiles. Results: The 75 controls and 168 patients selected were sex-matched. The patients were older, had larger spleens and lower platelet counts than controls. The relationship between spleen size and age in the controls and patients was quite similar. The patients in the first tertile of spleen size compared with those in the third were older and had a higher platelet counts. The underlying disease and dialysis vintage had no effect on spleen size. Discussion: The patients had larger spleens and a greater range of spleen sizes than the controls. In patients, the association between larger and smaller spleen with lower and higher platelet counts, respectively, sparked the speculation of occurrence of hypersplenism and hyposplenism.