Background <p>While there is increasing emphasis on initial implementation efforts, few studies have investigated the extent to which evidence-based parenting programs are still in use over time. Addressing this gap, this study examines the sustained use of an evidence-based parenting program five years after 16 practitioners became accredited program providers.</p> Methods <p>Through individual semi-structured interviews, we sought to (1) assess the extent to which the practitioners sustained or not sustained Standard Triple P use over time in Portugal’s child protection system and what factors influenced it and (2) explore the perspectives of practitioners, organizational managers, and system-level representatives of the child protection system bodies on the characteristics of this system that may be influencing the sustained use of evidence-based parenting programs, analyzed with the framework of strengths, weaknesses, opportunities, and threats.</p> Results <p>In the current study, five practitioners sustained Standard Triple P use within their organization up to five years post-accreditation. Our thematic analysis, underpinned by the Integrated Sustainability Framework, found that organizational factors played a stronger influence on both practitioners sustaining implementation and those who were non-sustainers. In addition, we identified strengths, weaknesses, opportunities, and threats that practitioners, organizational managers, and system-level representatives perceived to be promoting or limiting the sustained use of evidence-based parenting programs.</p> Implications <p>This study contributes with practical considerations into the sustained use of evidence-based parenting programs in real-world settings and underscores the importance of planning for sustainability to support program delivery over time, which is key to guaranteeing that such programs will reach the families that would benefit from them the most.</p>