A modified 'hot wall' technique (HWE) is used for growth of PbTe thin films directly on Si(100) high ohmic substrates both with and without any buffer layers. The previously formed SiO2 films have been used as buffer layers. The crystal microstructure of PbTe thin films has been studied by an etching pits method, SEM, RHEED and by X-ray analysis which is able to determine the X-ray rocking curve profiles and line width with high precision.. It has been found that these PbTe/Si and PbTe/SiO2/Si thin films have mosaic single crystal structure with (100) texture without regard to the Si substrate orientation. The investigations of PbTe/Si thin films dislocation density by the etching pits method and by the analysis of X-ray reflection profiles show the average values of about 10(5)-10(7) cm(-2). The experimental results of these methods have shown that PbTe/SiO2/Si thin firms had better crystallinity perfection. The average values of dislocation density were about 5 x 10(4)-2 x 10(5) cm(-2).