Pregnancy- and childbirth-related fears are common psychological concerns and the primary reasons for requesting caesarean section (CS). We aimed to examine the content of maternal fear and the associated demographic factors in a sample of Iranian primigravidae. A randomly selected sample of primigravidae (n = 342) was recruited in four health care centres in Iran. Data were collected using a 30-item questionnaire. Principal components factor analysis was applied to identify the main factors of pregnancy- and childbirth-related fears. All primigravidae reported some degree of fear, 48.2 % presented severe fear, and 62.6 % requested a CS because of childbirth-related fear. Most of the employed primigravidae with higher education level, higher family income, and unplanned pregnancy requested CS. The items constructed to measure maternal fear were subjected to exploratory factor analysis. Six categories were identified, including 'process of labour and childbirth', 'life and well-being of the baby', 'competence and behaviour of maternity ward personnel', 'own capabilities and reactions', 'becoming a parent and family life after delivery' and 'general fear in pregnancy' that cumulatively explained 55.3 % of the variance. The most common factor was 'life and well-being of the baby'. Severe fear was found in 70.6 % of those who chose CS, while 10.9 % of those who chose vaginal delivery reported severe fear. The between-group differences for mean scores and levels of fear were statistically significant. Pregnancy- and childbirth-related fears were frequently experienced by all low-risk primigravidae. Better strategies to address women's psychological needs during pregnancy are necessary.