Background: Hemodialysis patients are at high risk for developing Pneumocystis jirovecii pneumonia (PJP), and trimethoprim-sulfamethoxazole (TMP-SMX) is the first-line agent for treating this disease. However, there is a lack of consensus on the required dosage of TMP-SMX for hemodialysis patients. Methods: This study used the nationwide Japanese Diagnosis Procedure Combination database to review hemodialysis patients hospitalized for PJP from April 2014 to March 2022. Eligible patients were divided into high-dose and low-dose groups based on the median daily dose per body weight of TMP. The 90-day mortality and adverse events after propensity score matching were compared between the groups. Results: A total of 126 hemodialysis patients with PJP were included, and the median daily dose per body weight of TMP was 5.74 mg/kg/day (interquartile range: 4.33-8.18 mg/kg/day). Thirty-two pairs were analyzed after the propensity score matching. No significant differences in the 90-day mortality and proportion of adverse events were observed between the high-dose and low-dose groups. Conclusions: A high dose of TMP-SMX is unlikely to decrease the in-hospital mortality and adverse events among hemodialysis patients with PJP. However, the results should be interpreted with caution, given the lack of power and lack of long-term follow-up. Additional prospective interventional studies are required to validate these results.