The properties of Dirac gamma matrices in a four-dimensional space-tim
e with the (2, 2) signature are studied. The basic spinors are classif
ied, and the existence of Majorana-Weyl spinors is noted. Supersymmetr
y in 2 + 2 dimensions is discussed, and the existence of the real chir
al scalar supermultiplet is discovered. Supersymmetric self-dual Yang-
Mills theories and self-dual supergravity model in 2 + 2 dimensions, t
hat are apparently relevant to integrable systems, are formulated for
the first time.