A longitudinal vaginal septum can be obstructive or nonobstructive. We report on an adult woman who presented with involuntary fluid loss per vagina and had a partially obstructive longitudinal vaginal septum. A 36-year-old nulliparous female presented with malodorous, clear, leakage per vagina that she described as “urinary incontinence.” Examination revealed a fluid-filled fluctuant anterior vaginal wall with a draining sinus. Imaging revealed a solitary right kidney with duplicated ectopic fluid-filled ureters inserting into a partially obstructed left hemivagina with a longitudinal vaginal septum. A longitudinal vaginal septum may present in adulthood with the complaint of urinary incontinence.