ISAR (Inverse Synthetic Aperture Radar) images obtained from fully polarimetric 6-11 GHz measurements through a wooden wall of a static scene, containing a sitting human in a sparsely furnished room, have been enhanced with respect to the human-to-background power contrast by computationally varying the (elliptical) transmit and receive antenna polarizations. The contrast increase will facilitate detection of the static human target. The images were produced with an ISAR integration over 15° azimuth angle. Different images were obtained by viewing the scene from different look angles over a 150° azimuth range. No wall effects have been corrected for; the contrast improvement is applied to the actual signal at the receiving antenna. Two contrast enhancement methods have been tested and compared with the contrasts obtained with antennas that use one of the four Horizontal/Vertical (H/V) transmit/receive polarization combinations or one of the four Right Hand/Left Hand Circular (RC/LC) combinations. One method involves an iterative scheme, with target and background scattering description based on the Kennaugh matrix, calculated pixelwise in the ISAR image from the scattering matrix elements in the H/V base. The other scheme, based on scattering description with the covariance matrix, produces via a generalized eigenvector problem a polarimetric weighting vector whose components contain the antenna polarization vectors of the transmit and receive antennas to improve the contrast. The highest contrast increase was obtained with the iterative procedure, typically of the order of a few dB relative to the fixed H/V or RC/LC combinations in the covered aspect interval. A general trend was found for the optimized transmit/receive polarizations to be nearhorizontal or near-vertical as well as near-orthogonal, making a fixed polarization, crosspolarized (HV or VH) choice for the transmit/receive antennas a reasonably good one, if an optimization is not possible. However, the power levels obtained with cross-polarized transmit/receive antennas are significantly lower than in co-polarization, which may create problems in system implementation.