The N-methyl-D-aspartate receptor plays a crucial role in developmental plasticity. Evidence shows that neonatal exposure to N-methyl-D-aspartate receptor antagonists impairs cognition in adult rats. This study investigated whether neonatal MK-801 treatment would produce long-term and age-specific effects on working memory and sensorimotor gating in adolescent and adult female rats. After treatment with MK-801 at postnatal days (PND) 5-14, female rats exhibited slightly impaired working memory during adolescence (PND: 35-42). In contrast, working memory was remarkably disrupted in adult (PND: 63-70) female rats. However, prepulse inhibition and startle amplitudes were not significantly affected at both ages. These findings indicate that neonatal MK-801 elicits working memory deficits, especially in the postpuberty female rats.