Fifty-three consecutive infants younger than 2 years underwent coarctation repair. A recoarctation occurred in 11 infants (21%). To determine variables associated with recoarctation, we entered preoperative and operative data into a multivariate stepwise logistic regression analysis. Patient weight was an incremental risk factor for recoarctation instead of age, in contrast to previously published studies. Furthermore, the residual gradient after the operation was a strong incremental risk factor. This risk factor was even more significant when expressed as a ratio of the systolic arm pressure, which takes background hemodynamics into account. Because weight is a more significant risk factor than age, we conclude that deferring operation is indicated only when the infant gains weight. Furthermore, a residual gradient is more important in the hemodynamic setting of a lower systolic arm pressure.