trying to find my brother who was adopted but dont know his last name

Try going to the hospital in which he was born.. They should have records of all births & adoption records.

SuperrMommyy, unfortunately, in all but 7 states, adoption records are sealed and can only be opened by a judge which hardly ever happens.

OP, what do you know?

I am so sorry. I can't imagine. My own son has older siblings and his birth mother is very private. She did not want other family members to have our information, just her. When she no longer continued contact it cut my son off from his maternal family. I wonder if they think about him and want to have contact. If you have the ability, perhaps a private investigator? I'm not sure, but that is where I plan on starting. I would encorage to keep trying and searching. I know I would be delighted to establish contact with my son's siblings.

If you know for sure when and where he was born you could try some of the reunion sites. You might get lucky and he may be searching on the same sites.