We report the first case of unilateral spontaneous Descemet membrane detachment (DMD) with tear occurring in a patient with osteogenesis imperfecta (OI). A 20-year-old male patient with OI presented with a history of recent primary repair (2 weeks prior) of left globe rupture following local finger trauma to the left eye. The patient had no history of other ocular surgery or trauma. The examination revealed a best corrected visual acuity of 20/40 in the right and no light perception in the left eye. Slit-lamp examination showed an oval giant Descemet tear extending from the 12 o'clock to the 5 o'clock area and a large DMD involving the upper and nasal quadrants in the right cornea. It was thought that monitoring the patient without intervention and only considering a surgical procedure if the disorder progressed was the best option, taking into account the patient's reasonable visual acuity and the risks of keratoplasty. The dimensions of the DMD and tear had remained the same at 1-year follow-up period. We believe that follow-up without intervention should be considered for non-progressive DMD with a giant tear if the patient has a single functional eye.