84 men with primary sterility averaging 3.5 years and secondary sterility for 5.5 years with varicocele were treated with Yvanissevich's operation. 43 impregnated their wives within about 15 months, resulting in 33 term births, 9 miscarriages, and 1 extrauterine pregnancy. 80% of the spermograms were oligospermic before the operation. 50% of those whose wives conceived showed improved spermograms, and 37% of the men whose wives failed to conceive had improved spermograms. 50% of the men with normal testicles, 33% of those with unilateral testicular hypoplasia, and 40% of those with bilateral hypoplasia showed improved spermograms. Long thin spermatozoa did not appear to be characteristic of men with varicocele.