In pediatric ophthalmology, test results may be limited by a child’s ability to cooperate. Invasive and contact methods such as applanation tonometry, ultrasound biometry, and pachymetry are sometimes difficult to perform. Optical coherence tomography (OCT) has become a widely used noncontact method to obtain cross-sections of various ocular structures. In this review, we describe the principles and clinical applications of OCT, with special attention to pediatric ophthalmology. J Pediatr Ophthalmol Strabismus 2007;44:335-349. AUTHORS Dr. Salchow is from the Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut. Dr. Hutcheson is from Children’s National Medical Center, Washington, DC. Originally submitted July 10, 2007. Accepted for publication August 3, 2007. Address correspondence to Daniel J. Salchow, MD, Department of Ophthalmology and Visual Science, 40 Temple Street, New Haven, CT 06510.