Objective: This study is planned to assess the various risk factors of placenta previa such as with multi-parity, previous caesarean section and smoking. Methodology: This study conducted at the department of obstetrics and gynaecology, J.L.N.Medicalcollege, Ajmer from Oct 2009 to September 201. Detailed obstetrical and surgical history were documented. All those attending antenatal clinic in third trimester of pregnancy, 32 weeks onwards with or without symptoms of placenta previa and showing placental implantation in lower uterine segment and In the obstetric ward all the patients presented in emergency (unbooked) with antepartum haemorrhage and diagnosed as case of placenta previa by Ultrasound examination, were documented. Statistical analysis was performed using the Vasserstats software, Chi square test; Risk ratio and Percentage of incidence were used to show association of risk factors with PP, where appropriate. Results: Out of total admissions, 4000 patients at random were taken for the study.150 patients were diagnosed as placenta previa of various degrees. Out of the 150 PP patients, 72 were multipara, 65 were grand multipara and rest were primigrvida.400 patients had previous history of one or more caesarean section.85 patients are those who smoked, having placenta previa. Conclusion: The data of this study is concluded that there is a good association between increasing incidence of placenta previa with the increase in parity (p__ampersandsignlt;0.001), c-sections (p__ampersandsignlt;0.001), and smoking (p__ampersandsignlt;0.0001, RR=4.5, CI: 95).