  The possibility of charge density oscillations in a {\it finite-thickness}
two-dimensional system is investigated for strong magnetic fields and integer
filling factors. Using an effective action formalism, it is shown that an {\it
oscillatory charge density} (OCD) is generated in a self-consistent way and is
favored energetically over homogeneous distributions. It is smooth on the scale
of the sample thickness and of the magnetic length. The modulus of its wave
vector is shown to be experimentally accessible. The Hall voltage and the
current density are shown to {\it oscillate} with the same wave vector when a
weak current is applied. The stability of the charge oscillations against
impurity potentials is discussed.
