Can a biological father petition his biological son who has been adopted?

In order for your biological father to petition for you, you would have to break the adoption legally to be recognized as his son. I note that the waiting time for this category, F-3, is currently over 12 years even if all goes well, so you may well consider other avenues to immigrate. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.