Chronic absenteeism in early childhood is associated with numerous adverse outcomes throughout childhood and adolescence. Interventions are needed to prevent chronic absenteeism and support child development in early education. The present study investigated the effect of Primary Project, a school-based prevention program, on average school attendance among chronically absent students in kindergarten through second grade (N = 249). Results showed that students randomly selected to participate in Primary Project had a higher attendance percentage at the end of the year compared to the control group. This effect was not moderated by grade level nor by sex. Results show that Primary Project is a useful intervention for schools to improve student engagement "via" attendance.