Information on the administrative procedures for entering the adoption in the Swiss civil status register (Infostar):
Adoptions abroad are normally recognised in Switzerland when pronounced in the country of residence or citizenship of the adopter or adopting spouses (Federal Act on Private International Law (PIL SR 291)).
Many countries have signed the Hague Convention of 29 May 1993 on the Protection of Children and Cooperation in Respect of Intercountry Adoption (SR 0.211.221.311). This Convention sets rules for the cooperation between the relevant authorities of the child's country of origin and of the receiving State.
The website of the Federal Office of Justice holds useful information on the subject of international adoption.