Background: The third stage of labor has been described as the most dangerous stage. Concerning importance of the third stage, this study was performed to determine the length of this stage and its related factors.

Material s and Methods: This cross-sectional study was carried out on 1000 deliveries in shabihkhani Hospital, in Kashan, during 2005-2006. Gestational age >20 weeks, singleton pregnancy, and vaginal delivery without any instrument were the including criteria. Data were analyzed using c ² , OR and CI .

Results: Mean and median of the third stage of labor were 6.03 and 5 minutes, respectively. There was significant association between the number of parturitions (p= 0.04), induction with oxytocin (p=0.002), analgesia during labor (pethedin) (p=0.008), and umbilical cord drainage for the third stage management (p<0.001). There was no significant association between history of abortion, gestational age, third stage management (oxytocin), fetal sex, and weight.