Inpatient rehabilitation is crucial in the management of patients after injuries, surgery, or those with debilitating or neurological conditions. Orthostatic hypotension (OH) is commonly associated with these conditions, and therefore, the inability to stand and participate in rehabilitation therapy can negatively impact their recovery. To test this hypothesis, we study a cohort of 8352 patients who underwent rehabilitation at Vanderbilt Stallworth Rehabilitation Hospital between 2014-2019 to assess the prevalence of OH and its impact on the length of stay (LOS), functional independence measure (FIM) change (discharge FIM-admission FIM), and FIM efficiency (FIM change/LOS), compared to patients without OH admitted during the same period. We found that the prevalence of OH was 3.8% (n = 314; 60±18 yrs; 227 men). OH was commonly associated with patients admitted for neurological conditions (29%, n = 91), spinal cord dysfunction (22%, n = 71), orthopedic disorders (13%, n = 13), and stroke (10%, n = 33). On admission, patients with OH had a longer predicted LOS compared to those without OH (18±6
vs.
16±5 days, respectively,
p
= 0.001), reflecting greater medical complexity. Moreover, the actual LOS at discharge was significantly longer in OH patients compared to those without OH (19±12
vs.
13±9 days;
p
= 0.001) as was the difference between actual-predicted LOC (1±11
vs.
2±8;
p
= 0.001). The change in FIM was similar in both patients with and without OH (30±26
vs.
33±20, respectively;
p
= 0.52) but FIM efficiency was lower in OH patients (2±2.2
vs.
3±2.2 without OH;
p
= 0.001). OH prolonged LOS regardless of the admission diagnosis (stroke, other neurological conditions, spinal cord dysfunction and orthopedic disorders). In conclusion, OH is present in a significant proportion of patients undergoing acute rehabilitation and adversely impacts the recovery of these patients as measured by lower FIM efficacy and a prolonged rehabilitation period to achieve the same functional gain as patients without OH.