If total (PE + KE) is conserved:

Yes, According to law of conservation of energy the total energy of any system remains conserved (same).

Example.

If a body is placed at some height it possesses some potential energy.

As P. E = mgh

When this body is starting moving downwards its height becomes decreases so P. E decreases but at the same time it is moving I. e having some velocity. K. E = 1/2 (m) (v^2).

Hence here P. E decreases but K. E increases at the same time. So total energy is conserved.