Recurrent oral ulcerations are the most common pathologic condition seen by general dentists. Because the etiology of oral ulcers is diverse, it is a continuous challenge for clinicians to reach a correct diagnosis. Recurrent herpes simplex virus (HSV)-associated ulcerations mainly affect the lip (herpes labialis). However, intraoral ulcerations may also be a sign of recurrent disease. For many patients, these sores are painful and unsightly. Up to 85% to 90% of adults show serologic evidence of exposure to HSV. HSV infections can cause high morbidity beyond oral and genital lesions. Furthermore, HSV poses an infectious risk to both patients and oral health care providers, so it is important that dental professionals are up-to-date on appropriate therapies and precautions. This article discusses recurrent oral HSV infection and nonoral manifestations of HSV infection.