Cambial electrical resistance (CER) of Norway spruce (Picea abiesKarst.) was measured in relation to wood temperature. The linear function obtained was used to correct CER values from field experiments to a standard temperature. A fairly good correlation was obtained between the growth rate and CER of both dominant and suppressed trees. The average value of CER in a sample of spruce trees was relatively low in summer, increased by 100% in the autumn and started decreasing again the following March. Drought stress in a field experiment resulted in a significant increase in CER, which was inversely correlated with bark moisture. A review of the literature concerning the use of CER is presented, and the relevance of estimating CER is discussed, particularly regarding stress and diseases.