  Recent measurements of the correlation between the spin of the top and the
spin of the anti-top quark produced in proton anti-proton scattering at a
centre of mass energy of 1.96 TeV by the CDF and D0 collaborations are
discussed. Using up to 4.3 fb^-1 of data taken with the CDF and D0 detectors
the spin correlation parameter C, the degree to which the spins are correlated,
is measured in dileptonic and semileptonic final states. The measurements are
found to be in agreement with Standard Model predictions.
