A 3-year-old girl with a primitive neuroectodermal tumor (PNET) and a 6-yearold girl with acute lymphoid leukemia were referred to us because of problems with their implantable central venous ports (Port-A-Cath$^{(R)}$). On physical examination, the ports were upside-down, so a needle could notbe inserted through the membrane of the port. Right lateral side view of the chest radiogram confirmed port inversion in both cases. At operation, the ports were inverted and the transfixing sutures were totally absorbed. The ports were rotated 180 degrees and anchoring sutures placed.