  The whole class of minimally coupled and massive scalar fields which may be
responsible for flattening of galactic rotation curves is found. An interesting
relation with a class of scalar-tensor theories able to isotropise anisotropic
models of Universe is shown. The resulting metric is found and its stability
and scalar field properties are tested with respect to the presence of a second
scalar field or a small perturbation of the rotation velocity at galactic outer
radii.
