Since no commercial PSP Uncharted game exists, any downloadable "ISO" claiming to be Uncharted is either:

If you remember seeing an Uncharted game on a Sony handheld, you are not imagining things. You are thinking of Uncharted: Golden Abyss.

Developed by Bend Studio (creators of Days Gone), Golden Abyss was a launch title for the PlayStation Vita in 2011/2012. The PS Vita was the PSP’s successor, featuring a touchscreen, rear touchpad, dual analog sticks, and significantly more powerful hardware.

Searching for an "Uncharted PSP ISO file download" enters a legal gray area that every gamer should understand.

If you wish to play Uncharted on a handheld device, consider the following legitimate methods:

Because the keyword is popular, malicious actors target it. The "ISO" file might actually be an executable (.exe) file. If you run it on a PC, it could install ransomware, crypto miners, or keyloggers. If you put it on a modded PSP, it could brick your device. Always scan files with antivirus software before opening.

Users searching for this file are likely confused by the existence of Uncharted: Golden Abyss.

Before you proceed with any download, consider the following: