Compared with intraocular tuberculosis, ocular tuberculosis with ocular surface involvement is rare. Corneal involvement in ocular tuberculosis may include interstitial keratitis or peripheral ulcerative keratitis. We report a case of peripheral ulcerative keratitis directly caused by tuberculosis. A 20-year-old man complained of vision loss and pain in the left eye that had lasted for 1 week. A slit lamp examination of the left eye showed a corneal epithelial defect, interstitial corneal edema, and a white irregular infiltrative lesion and ulcer (with the dimension of 2 × 2.5 mm) in the inferior temporal region. The corneal ulcer was scraped, and the Mycobacterium tuberculosis deoxyribonucleic acid polymerase chain reaction was positive. After a month of oral antituberculosis treatment, the corneal ulcer resolved, and the intraocular inflammation improved. Peripheral ulcerative keratitis secondary to tuberculosis can be directly caused by M tuberculosis.