While a native PSP ISO is a myth, you aren't out of luck if you want to play RE4 on the go. Here are the most viable alternatives:
Emulators themselves are usually not illegal. However, downloading or distributing copyrighted game data without permission can be.
A buggy, crash-prone “proof of concept” that runs at 15-20 FPS. Most of these so-called “ISOs” are corrupted or fake. Resident Evil 4 Psp Iso Download
For years, this caused confusion in the gaming community. Players would download an ISO expecting the full console experience—third-person shooting, engaging cutscenes, and high-fidelity graphics—only to find a top-down, simplified version of the game. While it features Leon S. Kennedy and some familiar locations, it is not the same game found on the PlayStation 2 or GameCube.
To understand the ISO you are looking for, you have to understand the history. Despite the massive popularity of the PSP, Capcom never officially ported the mainline Resident Evil 4 to the system in the West. This is a surprising fact, given that the game was ported to the PlayStation 2, GameCube, Wii, PC, iOS, and even the Zeebo. While a native PSP ISO is a myth,
Load the ISO file into your chosen PSP emulator to play the game.
A Fake File: Many sites claiming to host a direct ISO of the game are actually providing "clickbait" files that could contain malware or unrelated data. The Best Ways to Experience Resident Evil 4 on Handhelds A buggy, crash-prone “proof of concept” that runs
Simply place the ISO file on your PSP memory stick and play it using your PSP.
There was never an official release of Resident Evil 4 for the PlayStation Portable (PSP). While the game has been ported to over 15 systems, including Android, iOS, and even the Zeebo, Capcom never released a native version for the PSP. The Reality of "Resident Evil 4 PSP" Files