objective: to evaluate the safety of instrumental vaginal delivery in women with history of cesarean section between 12 to 24 month previous. method: descriptive, transversal and correlational study of 40 patients that spontaneously initiated labor between march and october 2005. vaginal instrumental delivery was performed if the indication of previous cesarean section not persisted. interdelivery interval and lower segment thickeess were evaluated in relation to dehiscence. setting: maternidad ？concepcion palacios？, caracas. results: three patients had dehiscence of uterine segment, 2 with an interval between deliveries greater than 18 months, without statistical significance. there were significant differences in relation to: lower segment thickness, total dose of oxitocyn and duration of labor. conclusion: after 12 months of cesarean section, instrumental vaginal delivery is recommended in selected patients.