To determine whether in women with a twin pregnancy, mid-trimester cervical length is associated with the risk of emergency caesarean section. This study was a secondary analysis of two randomised trials conducted in 57 hospitals in The Netherlands. We assessed the univariable association between risk indictors, including mid-trimester cervical length in quartiles, and emergency caesarean delivery using a logistic regression model. In multivariable analysis we assessed whether adjustment for other risk indicators altered the associations found in univariable (unadjusted) analysis. Separate analyses were performed for suspected foetal distress and failure to progress as indication for caesarean section. There were 311 women with a twin pregnancy who attempted vaginal delivery after 34 weeks of gestation. Emergency caesarean delivery was performed in 111 (36%) women, of which 67 (60%) were performed because of arrest of labour. There was no relation between mid-trimester cervical length and caesarean delivery (aOR 0.97; for CL p26-50, aOR 0.71 for CL p51-75 and aOR 0.93 for CL >p75 with CL ≤p25 as reference). In multivariable analysis, the only variables associated with emergency caesarean delivery were maternal age (OR 1.07; 95% CI 1–1.13) BMI (aOR 3.99 (95% CI 1.07-14.9 for BMI 19–23, aOR 5.04 (95% CI 1.34-19.03) for BMI 23–28 and aOR 3.1 (95% CI 0.65-14.78) for BMI >28) and induction of labour (OR 1.9; 95% CI 1.05-3.5). In nulliparous women with a twin pregnancy, mid-trimester cervical length is not associated with emergency caesarean delivery.