<b><i>Background:</i></b> Mortality in the immediate post-hemodialysis transition period is extremely high. Many end-stage renal disease (ESRD) patients in the US start dialysis in an inpatient setting, but the characteristics of patients starting dialysis as inpatients, and the association of inpatient hemodialysis transition with mortality remain unclear. <b><i>Methods:</i></b> We examined 48,261 US veterans who transitioned to hemodialysis between October 2007 and September 2011. Associations of inpatient hemodialysis starting with all-cause mortality were examined in Cox proportional hazard models, with adjustments for demographics, comorbidities, vascular access type, pre-dialysis nephrology care and medication use, and last pre-ESRD estimated glomerular filtration rate and hemoglobin. <b><i>Results:</i></b> A total of 22,338 (46.3%) patients received the first hemodialysis treatment in an inpatient setting. Inpatient hemodialysis transition was associated with older age, presence of a tunneled catheter, higher comorbidity burden, and lack of pre-dialysis nephrology care. A total of 8,674 patients died (mortality rate 405/1,000 patient-years, 95% CI 397-413) during the first 6 months after transition to hemodialysis. The starting of inpatient vs. outpatient hemodialysis was associated with significantly higher crude all-cause mortality, but this association was attenuated after multivariable adjustments. <b><i>Conclusions:</i></b> Transition to hemodialysis in an inpatient setting is more common in older and sicker individuals, and in patients without pre-dialysis nephrology care and those who used a catheter for vascular access. Future studies are needed to determine if a higher proportion of patients could start hemodialysis treatment in outpatient clinics, through interventions targeting modifiable risk factors such as timely vascular access placement or earlier nephrology referrals.