AbstractAutobiographical memory is a cognitive function strongly related to emotional processing as autobiographical memory often includes emotional content. The COMT gene Val158Met polymorphism is associated with both cognitive and emotional processing. COMT gene Val158Met polymorphism effects on the emotional content and quality of Estonian schoolchildren’s first autobiographical memories were investigated in the present study. In addition, gender effects were considered and the emotional valence of the first memory was taken into account. Schoolchildren’s (N = 234) first memories were coded for valence, emotion words, specificity, and details. Girls were more likely to provide specific memories and recollections with an emotional valence than boys were. Children described memories with a positive or a negative valence in more detail than neutral memories. Interactions between the COMT gene Val158Met polymorphism and gender and valence of the events were detected: Val/Met heterozygotes provided fewer details for emotional events; Val/Met heterozygote boys reported fewer details for their first memories than Val/Met heterozygote girls did; Met/Met homozygote children provided fewer evaluative details for emotional events.