Kojima Productions have announced that the combined sales of all the Metal Gear games stands at a staggering 38.6 million sold worldwide.
This means the series has sold over a million more games since the last batch of figures were released in February. Most of these will probably have been the release of Ground Zeroes. This number will no doubt increase when the highly anticipated Metal Gear solid V: The Phantom Pain releases.
Source: Metal Gear Informer