Being a parent influences both parent’s and children’s well-being in many ways; therefore, developing interventions that support parents in their important role as a parent is vital. The current study evaluated the effect of an eight-week Flourishing Families parental intervention on interpersonal mindfulness, emotions and strengths in parenting in Finland. Randomly allocated to intervention and wait-list control groups were 63 parents. In addition to questionnaires, parents completed 5-day mobile Experience Sampling Method (ESM) assessments, both at pre- and post-intervention. The questionnaires were repeated at a follow-up 3 months after the intervention. Data analysis involved two datasets: randomized and pooled. The findings of this study suggest that participation in the Flourishing Families program can improve interpersonal mindfulness in parenting, shift emotional balance towards more positive emotions and less negative emotions, and enhance awareness and usage of own strengths. The results were more evident in the pooled data. With these preliminary findings, we hope to inspire both further positive psychology intervention (PPI) studies in the parenting context and the use of repeated momentary assessments.