  By invoking the concept of twisted Poincar\' e symmetry of the algebra of
functions on a Minkowski space-time, we demonstrate that the noncommutative
space-time with the commutation relations $[x_\mu,x_\nu]=i\theta_{\mu\nu}$,
where $\theta_{\mu\nu}$ is a {\it constant} real antisymmetric matrix, can be
interpreted in a Lorentz-invariant way. The implications of the twisted
Poincar\'e symmetry on QFT on such a space-time is briefly discussed. The
presence of the twisted symmetry gives justification to all the previous
treatments within NC QFT using Lorentz invariant quantities and the
representations of the usual Poincar\'e symmetry.
