We investigate the possibility of parity being spontaneously violated in QCD at finite baryon den sity and temperature. QCD is approximated by a generalized σ model with two isomultiplets of scalars and pseudoscalars. The mechanism of parity violation is based on interplay between lightest and heavier degrees of freedom and it cannot be understood in simple models retaining the pion and nucleon sectors solely. We argue that, in the dense and hot nuclear matter of a few normal densities and moderate temperatures, parity violation may arise due to a secondorder phase transition and its occurrence is well compatible with the existence of stable bound state of normal nuclear matter.