The use of heterodyne and quasi-heterodyne techniques in holographic interferometry allows a quantitative evaluation of the interference phase with high accuracy and offers the possibility of automated interferogram processing. In this paper, the fundamentals of these electronic methods are reviewed, the possibilities and limitations are discussed, and some applications in the field of displacement and strain measurement are presented. Heterodyne holographic interferometry is well suited for scientific applications in which very high accuracy (1/1000 of a fringe) is needed. Quasi-heterodyne holographic interferometry with video processing is adequate for industrial applica-tions in which high speed and medium accuracy (1/100 of a fringe) are required.