The Milky Way galaxy takes a very long time to complete one rotation. It's estimated to take around 200 to 250 million years for the Milky Way to make a full rotation.

This is based on the observed rotation speeds of stars and gas clouds at various distances from the galactic center.

It's important to note that the Milky Way is not a solid object, so different parts of the galaxy rotate at different speeds. The stars further out from the galactic center move slower, while the stars closer to the center move faster.