The object of the present paper is to find necessary and sufficient conditions for invariant submanifolds of trans-Sasakian manifolds to be totally geodesic. As a remark, particular cases of submanifolds of α-Sasakian and β-Kenmotsu manifolds are considered and the difference between the conditions for submanifolds of α-Sasakian and β-Kenmotsu manifolds to be totally geodesic is shown.