Thin epitaxial n‐PbTe films of various thicknesses are grown on KCl substrates by hot wall epitaxy (HWE) technique. The X‐ray, SEM and TEM studies of these films revealed their single‐crystalline nature. The Hall mobility (μH) of these films is measured by Van der Pauw technique and compared with the numerically calculated values for PbTe. It is observed that μH very strongly depends on thickness for thin films but becomes independent of film thickness beyond 5 μm approaching its bulk value. The constant value of Hall coefficient in the temperature range 77 to 300 K show the extrinsic nature of these films. It is also noticed that the rate of increase of mobility with decreasing temperature becomes higher with film thickness. The diffused scattering mobility due to the size effect is calculated and compared with experimental data. A large discrepancy observed between these two is explained on the basis of the residual mobility contribution. The residual mobility is attributed to overall scattering due to grain boundaries, dislocations, defects, cleavage steps, and other surface effects. Copyright © 1985 WILEY‐VCH Verlag GmbH & Co. KGaA