Full text article. Also available at https://doi.org/10.1016/j.jtumed.2021.01.009This study aimed to determine the prevalence of modes of delivery and associated maternal and newborn outcomes among singleton primigravidae in the Iringa region of Tanzania. A cross-sectional, analytical hospital-based study was conducted in the Iringa region among 356 singleton primigravidae between April and August 2018. Convenience sampling and consecutive collection of data using a face-to-face interviewer-administered questionnaire was done. A total of 356 singleton primigravid women with a mean age of 22.0 years (range: 15–49) participated in the study. The majority of the participants (73.0%, n = 250) were in the 20–35 age group. Caesarean and vaginal delivery were performed in 41.3% (n = 147) and 58.7% (n = 209) of the cases, respectively. The maternal height and weight of the newborn were significantly associated with caesarean delivery; (p = 0.001) and (p = 0.029), respectively. After adjusting for all variables, birth asphyxia (AOR = 3.25, 95% CI: 1.867–5.646, p = 0.000) and low birth weight (AOR = 0.03, 95% CI: 0.003–0.211, p = 0.001) were associated with caesarean delivery. The findings of our study indicated the prevalence of caesarean section to be three times more than that recommended by the World Health Organization. Pregnant women with a height of less than 150 cm should be considered for caesarean section. Therefore, it is necessary for stakeholders in the health sector to formulate guidelines for absolute indications for caesarean section.