Inclusion Criteria:

          -  Refractory AML without complete remission (CR) after induction therapy (primary
             induction failure) or relapsed AML after obtaining a CR. Disease defined by one of the
             following:

             *≥ 5% blasts in the bone marrow (M2/M3 bone marrow), with or without extramedullary
             disease

             *absolute blast count greater than 1,000 per microliter in the peripheral blood with
             or without extramedullary disease.

          -  Age requirement for pediatric cohort: 1-21 years of age.

          -  Available HLA-haploidentical donor that meets the following criteria:

               -  Related donor (parent, sibling, offspring, or offspring of sibling)

               -  At least 18 years of age

               -  HLA-haploidentical donor/recipient match by at least Class I serologic typing at
                  the A&B locus.

               -  In general, good health and medically able to tolerate leukapheresis required for
                  harvesting the NK cells for this study.

               -  Negative for hepatitis, HTLV, and HIV on donor viral screen

               -  Not pregnant

               -  Voluntary written consent to participate in this study

          -  Patients with known CNS involvement with AML are eligible provided that they have been
             treated and CSF is clear for at least 2 weeks prior to enrollment into the study. CNS
             therapy (chemotherapy or radiation) should continue as medically indicated during the
             study treatment.

          -  Karnofsky/Lansky performance status > 50 %

          -  Adequate organ function as defined below:

               -  Total bilirubin < 2 mg/dL

               -  AST(SGOT)/ALT(SGPT) < 3.0 x upper limit of normal (ULN)

               -  Creatinine within normal institutional limits OR creatinine clearance > 50
                  mL/min/1.73 m2 by Schwartz formula or GFR (See Appendix B)

               -  Oxygen saturation ≥90% on room air

               -  Ejection fraction ≥35%

          -  Able to be off corticosteroids and any other immune suppressive medications beginning
             on Day -3 and continuing until 30 days after the infusion of the CIML NK cells.
             However, use of low-level corticosteroids is permitted if deemed medically necessary.
             Low-level corticosteroid use is defined as 10mg or less of prednisone (or equivalent
             for other steroids) per day.

          -  Women of childbearing potential must have a negative pregnancy test within 28 days
             prior to study registration. Female and male patients (along with their female
             partners) must agree to use two forms of acceptable contraception, including one
             barrier method, during participation in the study and throughout the DLT evaluation
             period.

          -  Ability to understand and willingness to sign an IRB approved written informed consent
             document (or that of legally authorized representative, if applicable).

        Exclusion Criteria:

          -  Relapsed after allogeneic transplantation.

          -  Isolated extramedullary relapse

          -  Circulating blast count >30,000/µL by morphology or flow cytometry (cytoreductive
             therapies including leukapheresis or hydroxyurea are allowed).

          -  Patients with any of the following diagnoses:

               -  Down's syndrome

               -  Acute promyelocytic leukemia (APL)

               -  Juvenile myelomonocytic leukemia (JMML)

          -  Uncontrolled bacterial or viral infections, or known HIV, Hepatitis B or C infection.

          -  Known hypersensitivity to one or more of the study agents.

          -  Received any investigational drugs within the 14 days prior to the first dose of
             fludarabine.

          -  Pregnant