We study f -biharmonic integral submanifolds and integral C-parallel submanifolds in generalized Sasakian space forms. As an application, we find the f -biharmonicity conditions for the integral and integral C-parallel submanifolds in Sasakian, λ-Sasakian, Kenmotsu and cosymplectic space forms. Finally, we give also some examples of f -biharmonic integral submanifolds in Sasakian space forms,