Prepubertal genital herpes simplex virus (HSV) infection is rare. A four-year old girl was consulted for red spots on genital. Spots were itchy six days before but became painful with genital discharge and pain on urination four days before. History of sexual abuse, oral or genital ulcers was denied. There were erythema, edema, multiple circular ul- cers with purulent discharge on labia minora. Gram examination showed leukocytes and Gram-negative cocci.Dark field and Tzanck examination were negative. Fecalysis was normal. IgG to HSV-1 were reactive in acute and con- valescence serum. Normal saline compress, fusidic acid cream, paracetamol, azithromycin, and aciclovir provided resolution of lesions. Assessment was genital ulceration due to first-episode nonprimary HSV infection, suspected due to HSV-1. Parents were educated on possible sexual abuse. Clinical manifestation, response to treatment and serology established diagnosis but cannot confirm etiologic subtype.