We describe the previously unreported condition of Hodgkin's lymphoma in a patient with Noonan syndrome caused by germ-line mutations (1507G > C, Gly503Arg) in exon 13 of the PTPN11 gene. PTPN11, encoding SHP-2, is the first identified gene for Noonan syndrome and also the first identified proto-oncogene that encodes a tyrosine phosphatase. This somatic mutation has ever been reported in juvenile myelomonocytic leukemia (JMML). Furthermore, the functional analysis of this mutant SHP-2 has shown it to have enhanced phosphatase activity. Mutational analysis of PTPN11 gene in cancer cells and understanding how SHP-2 contributes to oncogenesis will provide new insight into the pathogenesis of Hodgkin's lymphoma.