The investigation of the minimum bubble drive field (ΔH z,min) in ion-implanted 5-μm magnetic garnet films shows that it depends strongly on the implantation conditions such as the implantation energy and dosage. With increasing implantation energy and dosage adjusted so that the maximum damage level remains constant, the ΔHz,min decreases monotonically. Varying the dosage while keeping the implantation energy constant leads to a pronounced minimum in ΔHz,min. Reductions of the ΔHz,min by as much as 43% from that of the as-grown films have been achieved by using proper ion implantations. The ΔHz,min in an ion-implanted film is found also to be dependent on the applied in-plane field Hip. With increasing Hip, the minimum drive field increases until finally the as-grown value is reached. This behavior as well as the dependence of ΔHz,min on the different ion implantations can be explained qualitatively by a model, assuming a capping layer somewhat buried in the garnet film.