  We study the well formulation of the initial value problem of f(R)-gravity in
the metric-affine formalism. The problem is discussed in vacuo and in presence
of perfect-fluid matter, Klein-Gordon and Yang-Mills fields. Adopting Gaussian
normal coordinates, it can be shown that the problem is always well-formulated.
Our results refute some criticisms to the viability of f(R)-gravity recently
appeared in literature.
