The instrumental assistance of a second period of delivery is one of the more complex issues to be analyzed into the obstetrics practice because there are multiple factors related.Historically there were physicians for and against instrumental assistance of delivery. We can solve a complicated situation by the rigth use of forceps or vacuum into the skilled hands as we can produce maternal and neonatal morbidity with unwise use. Perhaps, the most important fact is that instrumental delivery constitute an valuable option in the final target of decrease the rate of cesarean section. In this article, I analyze several problems associated to instrumental delivery. Fisrt the subject of the training problem is argued over real numbers, and second, also over real numbers is analyzed the problems related with the technique, indications, outcomes and finally complications of the use of instruments to get a vaginal delivery.