Disorders of sex development are defined as conditions in which the chromosomal, gonadal, and anatomic sex is discordant. Patients usually present with atypical appearing genitalia. In the assessment of neonates with disorders of sex development, first, it is important to determine whether this situation requires prompt evaluation, and then the karyotype, hormone levels, and underlying etiology should be determined as soon as possible. All these procedures should be performed in the guidance of a multidisciplinary team in reference centers. As the physical examination of the infant is extremely important, the physcian should suspect and then perform a detailed history and physical examinationi and lastly plan the required laboratory and imaging procedures for the definite diagnosis. It is important not to be hurried in the choice of sex. The aim of this article, which includes the diagnostic and therapeutic approaches in infants with ambiguous genitalia, was to provide a common practice for all pediatricians.