Although amniotomy is becoming more popular, however in practice, its recommendation requires special attention, and its indication should be clear. This research aims at studying the impact of amniotomy on rate of cesarean section. This research paper is based on the results of an analytical cohort study which carried out at kosar hospital, Qazvin (Iran) 2008-2009. The population under study consisted of all admitted women (n=305) whose labor was induced by amniotomy. The patients were further divided into two groups including exposure group (n=174) and unexposure group (n=131) based on being in early phase and active phase, respectively. The statistical analysis was performed over the obtained data using t-test, chi-square. Cesarean section was significantly higher, (p=0/001) in the exposure group than in the unexposure group i.e. 19 (10/9%) vs. 2 (1/5%). It is observed that Nonprogressive labor during the first stage of labor is considerably higher in the exposure group (p=0/001). Also non-progressive labor during the second stage was (2/9%) in the exposure group and (1/5% ) in the unexposure group that revealed no significant difference Oxytocin prescription in the exposure group was (43/7% ) while in the unexposure group it was (4/6% ) revealing a statistically significant difference (p=0/000). Non-progressive labor during the first stage and oxytocin prescription were all higher in the early phase group than in the active phase group. It seems that early amniotomy may increase the need for cesarean section.