  Spherical symmetry for f(R)-gravity is discussed by searching for Noether
symmetries. The method consists in selecting conserved quantities in form of
currents that reduce dynamics of f(R)-models compatible with symmetries. In
this way we get a general method to obtain constants of motion without setting
a priori the form of f(R). In this sense, the Noether symmetry results a
physical criterium. Relevant cases are discussed.
