Inclusion Criteria:

• Be at least 18 years of age
• Have histologically or cytologically-confirmed malignant disease in an advanced incurable stage
• Have not received chemotherapy or radiation for >14 days (advanced cancer patients receiving hormonal therapy or targeted therapy that does not come with a recommendation for prophylactic anti-emetic therapy are eligible)
• Have chronic nausea that has been present for at least one week (worst daily score >3, 0-10 visual analogue scale) or vomiting at least five times over past one week
• Have serum creatinine < 2.0 mg/dl and SGOT or SGPT < 3 times upper limits of normal ≤120 days prior to registration
• ANC >1500 mm3 <120 days prior to registration
• Women of childbearing potential must consent to use adequate contraception throughout protocol therapy; females of childbearing potential must have a negative urine pregnancy test <7 days prior to registration.

Exclusion Criteria:

• Not be receiving treatment with another antipsychotic agent such as risperidone, quetiapine, clozapine, phenothiazine or butyrophenone for less than or equal to 30 days prior to registration or planned during protocol therapy (patients may have received prochloperazine and other phenothiazines as prior anti-emetic therapy)
• Not have concurrent use of ethyol
• Not have severe cognitive compromise
• History of CNS disease (e.g. brain metastases, seizure disorder)
• Concurrent use of amifostine, concurrent abdominal radiotherapy; concurrent use of quinolone antibiotic therapy
• Chronic alcoholism (as determined by the investigator)
• Known hypersensitivity to olanzapine
• Known cardiac arrhythmia, uncontrolled congestive heart failure or acute myocardial infarction within the previous six months
• History of uncontrolled diabetes mellitus (stable insulin dose and/or stable oral hypoglycemic agent permitted)
• Planned chemotherapy or radiation during the 7 days following study initiation.