Prevention and amelioration of the myriad effects of toxic stress on child development is a significant public health concern. Scalable programmes to address this concern are lacking. Attachment Vitamins (AV) is a novel universal prevention programme for parents of young children that is trauma-informed and addresses toxic stress within a psychoeducational framework. In this pilot study, 52 parents enrolled in AV parent groups, which involve 10 weekly 90-minute meetings led by two trained facilitators. Pre- and post-programme measures included parental sense of competence, emotion regulation, parenting stress, warmth and negativity toward the child. Participating parents were predominantly low-income with multiple adverse childhood experiences. From pre- to post-programme participation, Wilcoxon signed rank tests revealed statistically significant increases in parental sense of competence, emotion regulation, and warmth toward the child. AV is discussed as a scalable, universal programme to improve parental functioning in families with young children.