Sorne studles In the llterature han descrlbed a relatlonshlp between symptoms of acule appendlcitis and the menstrual cycle. Thls prospective study was undertaken to further elucidate this information and to veriíy the incidence oí appendicitls in each phase of the menstrual cycle. 400 young women with appendicitis were studied. The method or statistical analysis used was the Chi Square test.The appendicltls was more frequent in the luteal phase; but there was no difference of statistical significance between any one phase of the menstrual cycle (menstrual vs. luteal phase, p=0.928; menstrual vs. follicular phase p=0.422; and follicular vs. luteal phase, p=0.206). the normals appendices were 3.25% of the 400 cases. Our study shows that the female sex hormones might be not an important cause in the development or appendicitis. Furthermore, the knowledge of the phase of the menstrual cyc...