  The degree and the temporal evolution of linear polarization in the prompt
and afterglow emission of gamma-ray bursts is a very robust diagnostic of some
key features of gamma-ray bursts jets and their micro and macro physics. In
this contribution, I review the current status of the theory of polarized
emission from GRB jets during the prompt, optical flash, and afterglow
emission. I compare the theoretical predictions to the available observations
and discuss the future prospect from both the theoretical and observational
standpoints.
