Abstract: Methotrexate (MTX) is widely used in the treatment of both rheumatoid arthritis (RA) and psoriatic arthritis (PA) with a side effect of pancytopenia. However, very few cases of severe pancytopenia caused by low-dose MTX therapy have been described in chronic kidney disease. Pancytopenia occurred after using a single dose of MTX in three patients with chronic kidney dysfunction. While one patient died due to sepsis and multiple organ failure, the others recovered. The severity of MTX-inducedpancytopenia in our cases was likely related to the underlyingkidney disease. These cases suggest that uremic patients may develop severe fatal bone marrow toxicity even with a single dose of MTX. Therefore, close blood count monitoring after MTX treatment in this population would be beneficial.