IntroductionFunctional decline occurs during dialysis initiation, particularly in unplanned cases. To prevent unplanned hemodialysis, we aimed to identify associated factors from the first referral to the nephrology department to hemodialysis initiation and assess patient prognosis post‐unplanned hemodialysis initiation.MethodsThis retrospective study involved 257 Japanese patients initiating hemodialysis and compared patient characteristics based on whether hemodialysis was planned or unplanned at a single center. Patient outcomes were evaluated in collaboration with maintenance hemodialysis centers.ResultsUnplanned hemodialysis initiation correlated with heart failure history (p < 0.05) and infections like pneumonia (p < 0.001). Patients with unplanned hemodialysis initiation had a worse prognosis than those with planned initiation (p < 0.001), and multivariable Cox regression showed it as an independent risk factor for death (p < 0.05).ConclusionsHygiene and careful attention to heart failure may reduce unplanned hemodialysis and improve patient well‐being and healthcare efficiency. This retrospective analysis highlights crucial considerations for optimizing the initiation of hemodialysis.