The changes in grain boundary misorientations during plastic deformation of titanium were studied by means of the EBSD technique. The misorientation of all types of the grain boundaries including low- and high-angle boundaries, coincident site lattice (twin) and arbitrary boundaries, deformation-induced boundaries and the boundaries of the original grains was found to change during deformation. It was shown that the deformation may result in either increasing or lowering of the boundaries misorientation and different segments of the same grain boundary may develop principally differently. The most significant changes of the boundary misorientation were found to be associated with the boundary junctions. The change in misorientations during deformation was discussed interms of the interaction of a boundary with dislocations and/or with other boundaries.