The study sought to investigate the influence of private cost on sustainability of Free Primary Education in Gacan-libaax and 26-June Districts, Somaliland. Private cost is the cost incurred by household, or individuals to support the provision of educational services. Sustainability is the propensity of a program to continue and to grow in time. After the Introduction of Free Primary Education in Somaliland, the rate of growth of formal public primary schools clearly indicated that a very little enrolment increased in which was not as expected as to grow while the tuition fees already abolished by the Somaliland government in early 2011. Teachers of public primary schools were act a high rate of migration from low motivated schools to higher motivated schools on the bases of private cost for the last two years. Influence of private cost have been suggested as significantly influencing sustainability of Free Primary Education, but their influence on public primary schools in Gacan-Libaax and 26-June districts have not been investigated. The purpose of this study was ascertain the influence of private cost on sustainability of Free Primary Education in Gacan-Libaax and 26-June