Objective To inform the decision to test and empirically treat for herpes simplex virus (HSV) by describing the initial clinical presentation and laboratory findings of infants with a confirmed diagnosis of neonatal HSV. Study design This is a retrospective case series performed at 2 pediatric tertiary care centers. Infants who developed symptoms prior to 42 days of age with laboratory confirmed HSV from 2002 through 2012 were included. We excluded infants <34 weeks gestation, those who developed illness before discharge from their birth hospital, and those who developed symptoms after 42 days of age. Results We identified 49 infants with HSV meeting these criteria. Most infants (43/49, 88%) came to medical attention at ≤28 days. Of 49 infants, 22 (45%) had disseminated, 16 (33%) central nervous system, and 10 (20%) skin, eye, mouth HSV disease. Eight infants (16%) had nonspecific presentations without the classic signs of seizure, vesicular rash, or critical illness (intensive care admission). All infants with nonspecific presentation were ≤14 days, had cerebrospinal fluid pleocytosis, or both. Conclusions The majority of infants with HSV (84%) presented with seizure, vesicular rash, or critical illness. A subset of patients (16%) lacked classic signs at hospitalization; most manifested signs suggestive of HSV within 24 hours. Further studies are needed to validate the risk factors identified in this study including age <14 days and cerebrospinal fluid pleocytosis at presentation.