Short answer. Under RA 8552, yes, an alien could adopt if their country had diplomatic relations with the Philippines, they had resided here for at least three years, and other conditions were met. But RA 8552 has been repealed by Republic Act No. 11642 (2022), so those specific conditions are no longer the current governing text.
What the law says
Any alien possessing the same qualifications as above stated for Filipino nationals
RA 8552, Section 7 — Who May Adopt. Read the full provision →
What the law says
That his/her country has diplomatic relations with the Republic of the Philippines, that he/she has been living in the Philippines for at least three (3) continuous years prior to the filing of the application for adoption and maintains such residence until the adoption decree is entered, that he/she has been certified by his/her diplomatic or consular office or any appropriate government agency that he/she has the legal capacity to adopt in his/her country, and that his/her government allows the adoptee to enter his/her country as his/her adopted son/daughter
RA 8552, Section 7 — Who May Adopt. Read the full provision →
What the now-repealed RA 8552 used to allow
Section 7 of RA 8552 addressed this directly, treating an alien as eligible on the same footing as a Filipino: any alien possessing the same qualifications as above stated for Filipino nationals could adopt, subject to additional conditions the section then listed. Under that provision, a foreigner adopting a child in the Philippines was a recognized path, not a general prohibition.
The conditions that route carried
Eligibility for an alien came with specific requirements: that his/her country has diplomatic relations with the Republic of the Philippines, that he/she has been living in the Philippines for at least three (3) continuous years prior to the filing of the application for adoption and maintains such residence until the adoption decree is entered, that he/she has been certified by his/her diplomatic or consular office or any appropriate government agency that he/she has the legal capacity to adopt in his/her country, and that his/her government allows the adoptee to enter his/her country as his/her adopted son/daughter. RA 8552 also allowed some of these, including the residency and certification requirements, to be waived in specific situations, such as a former Filipino citizen or someone married to a Filipino spouse.
RA 8552 has been repealed
This is no longer the governing statute. Republic Act No. 8552 was repealed in its entirety by Republic Act No. 11642 (2022). Domestic adoption is no longer processed as a court petition the way RA 8552 described; RA 11642 created an administrative process instead, run through the National Authority for Child Care, replacing the court-based procedure this article once set out.
What this means today
Because RA 8552 has been repealed, this article cannot tell you what the National Authority for Child Care currently requires of a foreign applicant. What can be said with confidence is that the specific residency and diplomatic-relations conditions quoted above are no longer the law being applied, and any foreigner adopting a child in the Philippines today proceeds under RA 11642's administrative process.