Investigation of the doped semiconductors is a large and interesting problem in the modern physics of semiconductors [1]. Study of the electronic properties of the narrow-gap PbTe, doped with different impurities, is stimulated by extensive use of AIVBVI semiconductors and their alloys in the infrared optoelectronics for manufacturing IR-lasers and detectors for the wavelength range extending from 1 to 40 μm [2]. However, the properties of the crystals doped during the growth process not just always correspond to the claimed requirements. In the present paper the influence of thermal annealing influence on the parameters and galvanomagnetic properties of Ga impurity doped PbTe crystals is brought. In the temperature range of 80-400K the galvanomagnetic properties of Ga impurity doped in various quantities PbTe crystals were studied. It is known that the undoped PbTe crystals usually posses the electrically active proper defects – the lead vacancies, the presence of which leads to the high values of holes concentration. The introduction of gallium impurities allows to control both the charge carriers concentration as well as the electrical conductivity type, which is related to donor type of gallium impurity in PbTe. The Ga impurity in the amount of 0,25 at. % and 0,5 at. % was added during the process of material synthesis. PbTe:Ga single crystals were grown by zone sublimation. The studied samples were of n-type conductivity and with the gallium concentration increase NGa the electron concentration was increasing by reaching at 80K the values of 3·1015 cm–3 and 5·1018 cm–3 accordingly. If in the sample with NGa= 0,5 at. % the electrons concentration practically does not depend on temperature (i.e. the pinning of the Fermi level is observed), then in the sample with the lower gallium content this dependence has an activation character. The activation energy determined from the lg n = f(1000/T) dependence slope, is of 70 meV, which indicates to the presence of donor levels related to gallium impurity [3]. The electrons mobility at 80К which is of 8000 cm2/V·s (0,25 at. % Ga) and 4000 cm2/V·s (0, 5 at. % Ga), rather strongly decreases with the temperature increase. By taking into account the power character of mobility temperature dependence from the slope of lgμ=f(lgT) curves the coefficient of ν = -2,6 was calculated, which indicates to the dissipation of charge carriers on to lattice thermal oscillations with the account of considerable dependence of the effective mass on temperature in PbTe. The isothermal annealing of the samples with NGa= 0,5 at. % was carried out in the hydrogen ambience at two temperatures of 5400С and 6500С during 100 hours. Some of samples were subjected to the thermal annealing at those temperatures with the intermediate investigation of galvano-magnetic properties. Independently on the annealing conditions the change of electrical conductivity type from n- to p-type was observed. The annealing at 5400С decreases the charge carriers concentration by 2-3 orders of magnitude (at 80К) and in the temperature range higher than 160К the charge carriers concentration increase with the temperature increase is observed with the activation energy of Еа ~ 150 meV. The charge carriers mobility in the annealed crystals considerably increased by reaching at 80К the values of 30 000 cm2/V·s, and at this in the temperature region up to Debye temperature (up to 160К) the portion of dissipation on optical phonons increases. The thermal annealing at 6500С decrease the holes mobility (up to ~ 9000 cm2/V·s), as the charge carriers concentration practically reaches the same values as at the annealing at 5400С. But with the temperature increase the charge carriers concentration increase is observed with the activation energy of ~ 340 meV. Such results could be explained by the formation of a ternary compound on the base of PbTe with the participation of gallium, which leads to the change in the band gap value.