The company said in a statement to Japanese media that it called off the events because it was concerned about the safety of the public.
The cancellations follow a rampage by a knife-wielding man in Tokyo at the weekend in which seven people were killed.
Despite the cancellations, sales of Metal Gear Solid 4: Guns of the Patriots will go ahead, and publicity events outside Japan will not be cancelled.
One of the cancelled launch events had been scheduled for Tokyo's Akihabara district, where the stabbing took place on Sunday.
Akihabara is home to hundreds of stores selling computers, electronics, video games and comic books. The area is a popular centre of youth culture that attracts hundreds of thousands of visitors at weekends.
Metal Gear Solid 4, the newest game in the popular series, will be released for the PlayStation 3 tomorrow. It has received favourable previews from critics and is expected to sell in large numbers.
Players control a soldier armed with a knife and various other weapons who fights his way through a multitude of enemies by killing and disabling them in a variety of missions.
In the Akihabara knife incident, a 25 year-old man allegedly drove a two-ton truck into a crowd of pedestrians and then ran through the area stabbing and slashing bystanders with a machete before being arrested.
Stabbings in Japan hit Metal Gear launch
By Simon Burns on Jun 12, 2008 2:16PM