Objective: To evaluate the outcome of endoscopic subureteral injection (ESI) in adults with vesicoureteral reflux (VUR) associated with decreased bladder compliance (D-BC). Methods: We retrospectively reviewed the medical records of 46 consecutive patients who underwent ESI for VUR at a single tertiary academic center. Fourteen patients (17 ureter units) who had underlying neurological disease with decreased bladder compliance, as determined by filling cystometry, were grouped as D-BC. Thirty-two patients (47 units) who had no signs or symptoms that suggested neurogenic lower urinary tract dysfunctions were grouped as normal bladder compliance (N-BC). We compared the cure rates for ESI between groups, defining cure as complete resolution of reflux on voiding cystourethrogram. Results: In 70.6% of the D-BC group and 70.2% of the N-BC group, VUR resolved completely after the first injection (P = 0.977). One failed unit of D-BC was cured after second ESI, and seven failed units of N-BC were cured after additional treatments (second ESI, two patients; ureteroneocystostomy, five patients). No additional treatments were applied to three units of D-BC or seven units of N-BC without symptoms. No complications related to the ESI were observed. Conclusions: The ESI was found to be effective in adults with VUR regardless of the bladder compliance. As a minimally invasive procedure with a favorable outcome, ESI may represent the first choice for treatment of VUR even in adults with D-BC.