The majority of children living in foster care in the United States have a history of maltreatment and/or disrupted caregiving. Maltreatment in early childhood adversely affects development at many levels, including neurobiology and behavior. One neurobiological measure associated with maltreatment is alpha electroencephalogram (EEG) asymmetry. Prior research has found greater right frontal asymmetry among children with a history of maltreatment. However, little research has been extended developmentally downward to examine alpha asymmetry and its behavioral correlates among toddlers in foster care; this was the purpose of the present study. Differences in EEG asymmetry were examined between a sample of foster toddlers (mean age = 3.21 years, n = 38) and a community comparison, low-income sample without a history of foster care (mean age = 3.04 years, n = 16). The toddlers in the foster care group exhibited greater right alpha asymmetry, primarily driven by differences in parietal asymmetry. Neither frontal nor parietal asymmetry were clearly related to internalizing or externalizing behaviors, measured concurrently or at previous time points. These findings reveal differences in alpha EEG asymmetry among toddlers in foster care, and highlight the need to better understand associations between neurobiological and behavioral functioning following early adversity.