An emerging literature suggests that maternal distress during the prenatal and perinatal period may adversely affect offspring development. The association between maternal stress and emotional status in the perinatal period (defined as 1 month after birth) and adjustment of first-grade children was examined in 948 mother-child dyads from the NICHD Study of Early Child Care using hierarchical multiple regression. Maternal demographic characteristics, including maternal education and income, accounted for 4% of the variance in Child Behavior Checklist (CBCL) externalizing scores when children were in first grade. Maternal stress and emotional status at 1 month accounted for an additional 4% of the variance in CBCL externalizing t scores; statistically significant contributions were made by maternal depression and perceived social support. Maternal depression and parenting stress at 1 month made statistically significant contributions to CBCL internalizing scores at first grade. These findings contribute to a growing body of literature indicating that perinatal maternal adjustment is associated with children's emotional and behavioral functioning years later. Implications for school psychologists' involvement in prevention, assessment, and intervention practices are discussed.