To provide a valve system drive device for a V-internal combustion engine capable of effectively using a space between both left and right banks.

In the valve system drive device for the V-internal combustion engine constructed to transfer torque from a crank shaft 7 to cam shafts (3L, 3R, 4L, 4R) of a left and a right bank via chains (10L, 10R) independently provided on the left bank 2L and the right bank 2R, one of chain tensioners (11L, 11R) applying predetermined tension on the chains (10L, 10R) is arranged in a chain tension side and another is arranged in a non-tension side (relax side), and both chain tensioners (11L, 11R) are provided between the left bank 2L and the right bank 2R.