Abstract:  We performed a prospective study of 1,000 neonates investigated in the first 72 hours of life in the health area of Ferrol (northwest of Spain) to assess the prevalence of erythema toxicum neonatorum, the anatomical sites most frequently involved, the influence of different maternal and neonatal parameters, day of life of medical examination, and type of delivery (vaginal or Cesarean). Overall prevalence of erythema toxicum neonatorum was 16.7%. Lesions most frequently involved the trunk, buttocks, and proximal areas of limbs. A higher prevalence of this dermatosis was found in Caucasian newborns (p = 0.01) and those with higher birthweight (p < 0.05), greater gestational age (p < 0.05), vaginal delivery (p < 0.05), maternal age of <30 years (p = 0.28), and fewer than two previous pregnancies (p = 0.12).