Let

be a connected real-analytic

-dimensional manifold,

be complete real-analytic vector fields on

which are linearly independent at some point of

, and

be real-valued controls. Consider the controllability of the system

. Necessary and sufficient conditions are given so that this system is controllable on any simply connected domain

contained in

on which

are linearly independent. These conditions depend on the computation of Lie brackets at those points where

are linearly dependent.