Premature childbirth is sometimes perceived as a painful and traumatic experience, in which mothers can manifest dissociative symptoms. Our study aims to evaluate dissociative symptoms during premature childbirth compared with full-term delivery and to identify predictors of perinatal dissociation. We conducted a cross-sectional, descriptive and analytical study, including 97 mothers of premature infants who presented to the outpatient unit of neonatology at the UH Hedi Chaker of Sfax in Tunisia. For each mother, we collected sociodemographic and obstetric data. We used the peritraumatic dissociative experiences questionnaire (PDEQ) for screening dissociative symptoms during labor. We assessed severity of prematurity by the perinatal risk inventory (PERI). Responses were compared with a control group of 80 mothers of full-term infants. Average age of mothers was 30.2 years. Average gestational age was 32.82 weeks. Pregnancies were single (83.5%) or twins. 77.3% of mothers gave birth by caesarean section. Prematurity was unexpected by 56.7% of them. According to the PERI, 47.4% of newborns were considered as high-risk preterm infants (PERI≥4). The average score of PDEQ was 16. The prevalence of perinatal dissociation for this sample (20.6%) was significantly higher compared with the control group (P=0.014). It was also correlated to unexpected prematurity (P<0.001) and a PERI score≥4 (P=0,023). Our results show that perinatal dissociation is more frequently occurring in preterm childbirth, especially when prematurity is severe and unexpected. Early interventions providing adequate information and support during delivery for mothers at risk of developing perinatal dissociation can alleviate such distress and prevent the development of subsequent post-traumatic stress disorder.