The ultimate goal in the treatment of cancer patients is the elimination of all tumor cells. A cure by surgery alone is possible only if the tumor is still confined locally. Detection of disseminated tumor cells may help to individually tailor the surgical procedure to each patient: extended or limited resections may be indicated depending on the individual state of tumor cell dissemination. In cases of systemic tumor cell dissemination, surgery alone cannot cure the patient. Thus, by detecting disseminated tumor cells, patients with a higher risk for relapse, who might benefit from multimodal therapeutic regimes, could be defined. A second aspect is the possibility of tumor cell shedding induced by manipulation during surgical procedures, which could be demonstrated for several tumor entities. Intraoperative tumor cell dissemination could be prevented by alternative operative strategies. In addition, perioperative antibody or cytotoxic therapy may prevent tumor cell implantation. Well-designed clinical studies are now of major importance to evaluate the clinical impact of individualized patient management and altered surgical procedures.