From 2004 onwards, above 50 seclusion reduction programs (SRP) were developed, implemented and evaluated in the Netherlands. However, little is known about their sustainability, as to which extent obtained reduction could be maintained. This study monitored three programs over ten years seeking to identify important factors contributing to this. We reviewed documents of three SRPs that received governmental funding to reduce seclusion. Next, we interviewed key figures from each institute, to investigate the SRP documents and their implementation in practice. We monitored the number of seclusion events and the number of seclusion days with the Argus rating scale over ten years in three separate phases: 2008–2010, 2011–2014 and 2015–2017. As we were interested in sustainability after the governmental funding ended in 2012, our focus was on the last phase. Although in different rate, all mental health institutes showed some decline in seclusion events during and immediately after the SRP. After end of funding one institute showed numbers going up and down. The second showed an increase in number of seclusion days. The third institute displayed a sustained and continuous reduction in use of seclusion, even several years after the received funding. This institute was the only one with an ongoing institutional SRP after the governmental funding. To sustain accomplished seclusion reduction, a continuous effort is needed for institutional awareness of the use of seclusion, even after successful implementation of SRPs. If not, successful SRPs implemented in psychiatry will easily relapse in traditional use of seclusion.