Efficacious parenting group interventions are not routinely available in public child mental health services in Greece. The present study aims to provide a pilot evaluation of a manualised group-based parent training (PT) program developed for use with Greek parents of young children with behavior problems presenting to clinics. The efficacy of an 8-session and an extended 10-session PT program were evaluated with 38 parents of 24 children, aged 4-7 years old. The results revealed significant reductions in parent reported child behavior problems and significant improvement in child psychosocial functioning for both PT programs, though with better intervention effects for the extended 10-session program. The acceptability of the format and the content of PT program as well as limitations and future research are discussed.