Due to continuous rise of cesarean section (CS) rate in recent decades to analyze this trend using Robson Ten Group Classification System (RTGCS) and identify the main contributor of the CS rate in an Italian tertiary level hospital.A total of 17,886 deliveries in six (1998, 1999, 2004, 2005, 2010, 2011) of a 13-year period was analyzed using RTGCS.From 1998 to 2011 a rising CS birth rate from 38.7 to 43.7 per 100 births was calculated (p<0.001) in association with a significant reduction of vaginal delivery (VD) (59.7 vs. 53.7%; p<0.001). In multiparous women with a previous CS (Group 5) a repeat CS was performed routinely, resultant the most contributor of CS rate (15.4 vs. 16.2%; p<0.001). Nulliparous women with singleton cephalic full-term pregnancy in spontaneous or induced labor onset resulted the second contributor (Group 1, 3.3 vs. 4.7%; p<0.001; Group 2, 3.6 vs. 4.5%; p<0.001).The RTGCS allows easy identification of the leading contributing patients groups. To propose and evaluate interventions for improving the labor management in nulliparous women and promote vaginal delivery after cesarean (VBAC) could help to mitigate further increases in the future.