Prenatal maternal internalizing psychopathology (depression and anxiety) and socioeconomic status (SES) have been independently associated with higher risk for internalizing and externalizing problems in children. However, the pathways behind these associations are not well understood. Numerous studies have linked greater right frontal alpha asymmetry to internalizing problems; however, findings have been mixed. Several studies have also linked maternal internalizing psychopathology to children's frontal alpha asymmetry. Additionally, emerging studies have linked SES to children's frontal alpha asymmetry. To date, only a limited number of studies have examined these associations within a longitudinal design, and the majority have utilized relatively small samples. The current preregistered study utilizes data from a large prospective study of young children (N = 415; Meanage = 7.27 years; Rangeage = 5–11 years) to examine the association between prenatal maternal internalizing symptoms, children's frontal alpha asymmetry, and behavior problems. Prenatal maternal internalizing symptoms did not predict children's frontal alpha asymmetry, and there was no association between frontal alpha asymmetry and behavior problems. However, mothers’ internalizing symptoms during pregnancy predicted children's internalizing and externalizing outcomes. Non‐preregistered analyses showed that lower prenatal maternal SES predicted greater child right frontal alpha asymmetry and internalizing problems. Additional non‐preregistered analyses did not find evidence for frontal alpha asymmetry as a moderator of the relation between prenatal maternal internalizing psychopathology and SES to children's behavior problems. Future research should examine the impact of SES on children's frontal alpha asymmetry in high‐risk samples.