•Seaport efficiency is very essential to international trade flows and the trade balance.•Notwithstanding the efficiency of seaports, there is dearth of evidence on how it influences the trade balance.•This study investigates the effect of seaport efficiency on the trade balance in a sample of 27 African countries.•The findings suggest that seaport efficiency improves the trade balance the trade balance in the short- and long-run periods.•Enhancing the efficiency of seaports in Africa is what policy reforms should target. Seaports and their efficiency are particularly important for international trade flows and the trade balance. Notwithstanding the efficiency of seaports, there exists no empirical evidence on how it influences the trade balance. This paper provides empirical evidence on the effect of seaport efficiency on the trade balance in a sample of 27 African countries for the period 2010-2017. We do this with the aid of the dynamic system Generalised Method of Moments (GMM) estimation technique, which addresses potential endogeneity of regressors. The results suggest that seaport efficiency improves the trade balance in the short- and long-run periods. From a policy-oriented point of view, enhancing the efficiency of seaports in Africa is what policy reforms should target.