Background
Caesarean section (CS) is associated with an increased risk of adverse health outcomes for both mothers and offspring. The evidence for an association between CS and reduced offspring cognitive and academic performance has been inconsistent, with considerable limitations.

Aim
The aim of this study is to compare cognitive and academic performance in childhood and early adulthood in offspring delivered by CS with those delivered vaginally at term.

Materials and methods
Data on 4327 mothers and offspring from a longitudinal birth cohort study were analysed. Offspring cognitive performance was measured by the Picture Peabody Vocabulary Test‐Revised (PPVT‐R) at ages five and 21 and the Raven’s Standard Progressive Matrices at age 14. Academic achievement was assessed using the Wide Range Achievement Test at age 14.

Results
After adjustment for confounding factors, there was no statistically significant association between cognitive performance and offspring birth mode at age five (P = 0.11). The adjusted difference of mean scores at five years on the PPVT‐R for elective CS birth compared to those born by vaginal delivery was −2.2 (95% confidence interval (CI) −4.3 to −0.2), whereas for emergency CS it was 0.0 (95% CI −2.0 to 2.0). There were no differences in cognitive or academic performance at ages 14 and 21.

Conclusion
Birth mode was not significantly associated with offspring cognitive or academic performance. Our study does not support concerns that CS is associated with a reduction in cognitive performance.