Objective: The aim of this study is to investigate the level of knowledge of the pregnant women about their pregnancy and factors that affect it. Methods: Our study group is consisted of 314 pregnant women between 18-50 years of age with different trimesters who had admitted to Ondokuz Mayis University Medical Faculty Department of Gynecology and Obstetrics. After their demographic, obstetric and general health, perinatal care management were investigated, a questionnaire consisted of 70 items which they should know about their perinatal period (physiological changes, health promotion and follow up) were applied. The pregnant women divided into three groups according to the number of the true answers as not sufficient , medium (2447) and sufficient (>48). Different factors that might affect the level of knowledge of the pregnant were investigated statistically. Results: The 54% of the cases that are included in our study are between 26-35 ages while 34.9% of them had elementary school education, 74.6% of them are housewives. 33.3% of them got pregnant for the first time while 68.6% of the pregnancies were planned. The subjects gave 55.39±6.63 true answers to these 70 items. 86.7% of the pregnant women had sufficient levels of knowledge while 13.3% of them had moderate and none were in not sufficient group. In a regression model analyzing the relationship between level of pregnant women's' knowledge with demographic, obstetric and general health, follow-up features and data gathering methods, age (p<0.001) and level of education (p=0.002) were found as independent factors. Conclusion: Our study has revealed that the knowledge level of the pregnant women about their pregnancy is found to be average or good, and these levels are affected by age and education level but, not affected by health service institutions or physicians they receive care.