To describe palpebral fissure changes during early childhood. Digital imaging was used to analyze the monocular palpebral fissure images of 185 children and 35 adults. Six variables were quantified for each eye: the distance between the pupil center and the upper and lower eyelid margin, the palpebral fissure area, and the obliquity and length of the fissure. The lower eyelid crease pattern also was evaluated qualitatively. The upper eyelid was at its lowest position after birth, and the lower eyelid margin was close to the pupil center. Between ages 3 and 6 months, the position of the upper eyelid reached its maximum and then declined linearly. At the same time, the distance between the pupil center and the lower eyelid margin increased linearly until age 18 months when its position stabilized. Both the horizontal palpebral fissure length and the fissure area followed a logarithmic pattern of growth and were strongly correlated. The obliquity of the fissure was evident at an early age and did not change until adulthood. At birth, the most common pattern of the lower eyelid crease was a single crease. The number of individuals showing a double crease increased with age, and at approximately age 36 months, a double crease became the most common pattern. The palpebral fissure undergoes complex changes during infancy. An accurate knowledge of these changes is important for evaluating eyelid disorders in children.