Aim It is important to investigate the relationship between the beliefs about birth as a natural or medical process and the pregnancy-related anxiety that has a powerful impact on the negative outcomes of labor. This study was aimed at investigating the relationship between basic birth beliefs and pregnancy-related anxiety in Turkey. Methods This descriptive, cross-sectional and correlational study was conducted in a University hospital located in eastern Turkey. The study sample included 473 primiparae having completed 14 weeks of pregnancy. The Birth Belief Scale and Pregnancy-Related Anxiety Questionnaire/PRAQ-R2 were used to collect the data. Results A relationship was found between birth beliefs and pregnancy-related anxiety. Strong beliefs about birth as a medical process or weak beliefs about birth as a natural process were found to be related with fear of giving birth and worries about bearing a handicapped child. Conclusion A relationship was detected between beliefs of pregnant women about birth as a medical and natural process and fear of giving birth, worries about bearing a handicapped child., concern about own appearance. It is highly important to detect the birth beliefs in order to help women have a healthy pregnancy period and to decrease their anxiety levels. Pregnancy-related anxieties of women must be detected, and their birth beliefs that result in anxiety must not be overlooked during the provision of prenatal healthcare services.