- The main plot of the manga and the two anime series revolve around Ed scouring the earth for a way to restore his younger brother Al's body to normal. On the other hand, considering Al is inhabiting an animated suit of armor much larger than Ed, there's a quite unusual dynamic going on there. Especially considering how Ed reacts to anyone calling him short.
- In the manga and Brotherhood, Ed sacrificed his arm to keep his brother's soul in existence. And later, his use of alchemy altogether. If that's not Big Brother Instinct, what is?
- The Elrics both have this dynamic towards each other. Edward was more than once willing to die for Al (until he realized that if he died no one else would be able to put Al back to normal) — and Al did not approve of Edward's plan to let himself killed by Scar so latter one would leave Al alone.
- Scar's older brother, despite being a Non-Action Guy, also manages to pull this. When Kimblee attacked them in the Ishvalan War, he jumped in front of Scar even though the effort was... well, fruitless and he clearly knew it. Afterwards, as Scar lay dying with one arm gone, his brother sacrifices his own arm and bleeds to death in his place, ultimately giving Scar the chance to fight back against the Ancient Conspiracy.
- At the end of the 2003 anime, Alphonse sacrifices his recently Philosopher's Stoned self to revive his brother. Edward answers this with sacrificing himself to bring Al back. In the movie, they spend much time, stress and tears to find each other again after this ordeal, and although they succeed, circumstances are such that Edward decides to leave his brother for good and seal the Gate from his side, in order to protect Al and Amestris from Dietlinde Eckhart — and Al replies with following him to the far side to be with him. That's FMA for you...
- The first anime and one of the novels also feature the Tringham brothers Russell and Fletcher. Russell is very protective of his brother, though it takes him a while to realize that otherwise he's been neglecting him. He gets better.
Big Brother Instinct / Fullmetal Alchemist