GTA 5 does not work on the PlayStation Portable (PSP).
If you found a thread on PSPiso (or similar forums) claiming to have a downloadable version of GTA 5 for the PSP, it is not a legitimate port of the game. Here is the detailed breakdown of why and what you actually downloaded: pspiso club gta 5 work
Legit GTA games released for PSP:
You can find their ISOs legally if you own the UMDs (backup copies for personal use). GTA 5 does not work on the PlayStation Portable (PSP)
In the annals of handheld gaming history, there is a distinct, bittersweet chapter written in the forums of the mid-to-late 2000s. It was a time before the iPhone dominated pocket gaming, a time when the PlayStation Portable (PSP) was the undisputed king of the hill. And ruling over that kingdom, with an iron fist of custom firmware and ISO files, was the legend of PSPISO Club. You can find their ISOs legally if you
For those who lived through it, the mere mention of "PSPISO" evokes a specific feeling: the hum of a laptop fan downloading a compressed CSO file, the purple haze of the XMB menu, and the thrill of playing console-quality games on a bus ride.
But no memory is as potent, or as poignant, as the community’s obsession with a game that arguably killed the platform’s relevance: Grand Theft Auto V.