- "I'm placing these droids in your care. Treat them well. Clean them up. Have the protocol droid's mind wiped."
- ―Bail Organa to Raymus Antilles
A memory wipe, also known as a memory flush, was a procedure which totally erased the memory. In most of the Galaxy, memory wipes were used on droids. All databanks, except for basic factory-installed programming, were "wiped" clean. A memory wipe was performed with a memory flush unit.
Droids normally gathering experiences, gradually begin to develop personality and independence, even overriding their programming. These effects were unwelcome by most droid owners so they prevented it by performing regular memory wipes. Most droids tended to dread the procedure. But living beings have also gotten their memory wiped, too.
There was evidence, however, suggesting that not performing memory wipes could have beneficial side-effects. One such side effect was that the droid was better capable of inferring the wishes of its master, increasing its efficiency and accuracy. Also, droids with accumulated memories were often more effective because of their increased practical knowledge and real-world familiarity. Technicians working on Luke Skywalker's X-wing found that because Skywalker refused to wipe R2-D2's memory that the droid was needed to decipher diagnostics from the X-wing, but at the same time communications between Artoo and the ship had greatly improved as time went by.
The periodic application of memory wipes became commonplace sometime after 200 BBY, when a cybersociologist of the Baobab Merchant Fleet accidentally created a personality algorithm that ran rampant as a virus through the droid population.
Bail Organa ordered Raymus Antilles to wipe C-3PO's memory to ensure the true lineage of Leia Organa remained unknown. However, an image of a nine-year-old boy—the droid's maker, Anakin Skywalker—somehow survived the wipe. Years later, after the mention of Obi-Wan Kenobi's name, Owen Lars told Luke Skywalker to wipe the memory of two recently acquired droids—Threepio and Artoo—as part of a routine procedure. The wipe, however, was never performed.
Wedge Antilles had the memories of his Astromech Droid, Mynock, wiped after finding that in battle situations the droid's screaming was too much of a distraction. The technicians wiped Mynock's memory, and made a number of other improvements which resulted in the droid being re-designated R5-G8. Wedge then renamed the droid Gate.
During the days of the Old Republic a criminal organization called the Syndicat created a memory-wiping device for living beings. The Syndicat used this device to wipe the memories of the natives of Phindar who defied them, as a punishment. Obi-Wan Kenobi nearly had his memory erased, however, after surrounding his memories with the Force, he became the only being to ever withstand the memory wipe. It was destroyed by the natives in the battle that brought the end of the Syndicat in 44 BBY.