The current investigation reports the results of a randomized controlled trial of a brief, relational intervention for maltreated preschool-aged children and their mothers, called Reminiscing and Emotion Training (RET). RET facilitates elaborative and emotionally supportive parent-child communication, which is an essential component of the parent-child relationship and is especially relevant for the preschool age period. Participants were 248 children between the ages of 3- to 6-years-old and their mothers. Following a baseline assessment, 165 maltreating families were randomized into RET or a Community Standard (CS) condition in which families received case management and written parenting information; 83 families participated in the nonmaltreating comparison condition. Results indicated that the key mechanisms targeted by the RET interventions were enhanced, such that mothers who participated in RET were significantly better in elaboration and sensitive guidance during reminiscing at the posttest than were maltreating mothers who did not receive the intervention, with medium to large effect sizes; additionally, mothers in the RET group were more elaborative than mothers from the nonmaltreatment group. Children in the RET condition also contributed significantly more memories and had better emotional knowledge than did children in the CS condition, controlling for baseline values and language, and approximated the functioning of nonmaltreated children. These findings add to a growing literature underscoring the benefits of brief, focused, relational interventions for maltreated children and their caregivers. (PsycINFO Database Record (c) 2019 APA, all rights reserved).