Macaque monkeys do not reliably discriminate binocular depth cues until about 8 weeks of age. The neural factors that limit the development of fine depth perception in primates are not known. In adults, binocular depth perception critically depends on detection of relative binocular disparities and the earliest site in the primate visual brain where a substantial proportion of neurons are capable of discriminating relative disparity is visual area 2 (V2). We have examined the disparity sensitivity of V2 neurons during the first 8 weeks of life in infant monkeys and compared the responses of V2 neurons to those of V1 neurons. We found that the magnitude of response modulation in V2 neurons as a function of interocular spatial phase disparity was adult like as early as 2 weeks of age. However, the optimal spatial frequency and binocular response rate of these disparity sensitive V2 neurons were more than an octave lower in 2- and 4-week-old infants than in adults. Consequently, despite the lower variability of neuronal firing in V2 neurons of infant monkeys, the ability of these neurons to discriminate fine disparity differences was significantly reduced compared to adults. This reduction in disparity sensitivity of V2 neurons is likely to limit binocular depth perception during the first several weeks of a monkey's life.