This study examined the impact of pupil age at time of school entry in a large public school in Bronx, New York. Results from a literacy assessment were examined for kindergarten, first-, and second-grade students. The assessment rated children on their knowledge of the alphabet, sight-word vocabulary, phonemic awareness, reading, and writing mechanics. Test results were analyzed by birth date and gender. Findings indicated that: in kindergarten, 64 percent of children born in the first third of the year were at or above grade level on the alphabet/sight word portion of the test; 27 percent were at or above grade level on reading; and 4 percent were at or above grade level on writing mechanics. Findings for children born later in the year indicated that achievement did decrease with birth date, although not steadily. For first-graders, achievement decreased with birth date in the areas of alphabet, sight words, and reading, but did not consistently decrease in phonemic awareness or writing mechanics. For second-graders, achievement did decrease consistently with birth date in all testing areas, with the biggest gap between those born in the first and final thirds of the year. Also, female students achieved grade level more often than male students in almost all grades and months of birth. Based on these findings, it was concluded that moving the cut-off date for kindergarten entrance from December 31 to September 1 would help to lessen occurrences of failure among the youngest students. (Contains 18 references.) (EV)