The first national security strategy in the Republic of Croatia was adopted in 2002. Given the external pressures, the urgency and urgency of adopting the strategy was emphasized, due to which there was no professional and public discussion, which could have resulted in a higher quality of the strategy. The strategy focused mainly on the military-defense understanding of national security, which is an outdated understanding of the term. Nowadays, national security is viewed in a much broader context, consists of different elements and seeks to achieve different strategic goals. The National Security Strategy was finalized only in 2017, when the Homeland Security Act was passed, thus forming the national security system of the Republic of Croatia as it is known today. The 2017 strategy also states the demographic renewal and revitalization of Croatian society as a strategic goal. Demographic resources are one of the key factors in preserving national security. Without demographic development, favorable socio-economic or any other development is not possible, and in the case of negative demographic processes and trends, the issue of national security may be endangered. This is precisely the case in the Republic of Croatia, where for many years there have been trends of declining birth rates, natural and total depopulation and population aging. This was confirmed by the first result of the 2021 census, according to which Croatia lost 396,360 inhabitants, or 9.25% of the total population compared to 2011. The share of the elderly population also increased by 1.34%, which means that the natural increase in the future, especially if the scale of migration is taken into account, will be even more unfavorable. Although negative demographic processes and trends have been present for many years, not much has been done to improve the demographic situation. If measures of demographic renewal and revitalization of Croatian society are not urgently implemented, which will show some results in practice, Croatia is threatened with even greater proportions of the demographic crisis in the future, which could affect the national security system.