After having reported various opposite techniques for the treatment of dysplasia and in situ carcinomas of the uterine cervix, the authors present their experience with 125 cases of conisation, performed between 1984 and 1988. The electroconisation technique, performed in 88 cases, is compared with other conisation techniques: conisation with a cold scalpel, laser conisation. The use of a cold scalpel is simple and effective, but presents the disadvantage of peroperative (22.2% in our series) and secondary (7.4%) haemorrhages requiring preventive overlapping stitches which impede subsequent monitoring. Laser conisation seems long and tedious. On the contrary, electroconisation presents the advantage of being simple and quick, with very few peroperative (6.8%) or secondary (3.4%) haemorrhages, but two minor drawbacks: impeding pathological interpretations (1%), causing secondary stenoses which seem to be related to the height of the cone and not to the type of conisation.