The paper is devoted to the analysis of problems of humidity migration in autoclaved aerated concrete walls. It presents the methods for monitoring of humidity migration processes. Especial attention is paid to the analysis of condensation risk on the surface between the autoclaved aerated concrete block and outdoor finishing. The paper gives theoretical calculation of condensation risk in autoclaved aerated concrete wall as well as presents the results of practical measurements. For the purpose of practical measurements, two experimental walls, on the northern and southern part of the building, were built in Tallinn imitating real living space. The analyzed walls had been constructed using autoclaved aerated concrete blocks 375 mm in thickness, volume weight ≤ 400 kg/m3, glued together with a 2 mm thick layer of glue mortar. Starting from year 2005 the thermal measurements were carried out on the regular basis. The preliminary results of this experiment have shown that monitoring of humidity migration processes in autoclaved aerated concrete walls could be accurately done by cutting out test pieces and putting them on the scales. The influence of thermal qualities of autoclaved aerated concrete wall on the drying process of wall was also studied in the scope of this paper. As the result the dependences between heat conductivity coefficient and moisture content were developed.