Abstract. The size of the mesh used for surgical repair of groin hernias differs significantly from one technique to another. Such differences are not unimportant, since implantation of a large amount of prosthetic material can induce some drawbacks and may perhaps be avoided in many cases. The weak inguinal area, where inguinal hernias are exteriorized, is smaller than the myopectineal orifice, and a mesh 89cm long and 56cm wide is sufficient to cover this area. The results of methods using a small mesh are good, and large patches provide at best the same results with some real drawbacks. A large mesh spread in the preperitoneal space on the bladder and iliac vessels can induce some difficulties in case of further operation on these organs, and when we operate on a man 30 to 50 years old, we ignore whether he may need that kind of operation many years later. Consequently, in most cases a small patch covering only the weak inguinal area is preferable and a large preperitoneal patch should be used only in selected cases at high risk of recurrence.