OBJECTIVE: Recommendations on the appropriate use of corticosteroids (cort) and HT-3 antagonists (HT3A), alone or in combination with benzodiazepines (benz) and dopamine receptor antagonists (dopA) vary between three and nine different anti-emetic strategies. METHODS: We retrospectively compared the use of anti-emetics in our clinical practice with the consensus recommendations of Peruggia. We analyzed all patients from a single department unit receiving chemotherapy on an inpatient basis in February 2000. RESULTS: One hundred thirty five days of chemotherapy in 38 patients (20 - 78 years old, male/female 1,7/1) suffering from various malignant diseases were included. Five patients (13.1%) received anti-emetic therapy for other reasons than preventing nausea and vomiting (e.g. corticosteroids as comedication with paclitaxel). We grouped the chemotherapy in "very low risk" (n=5), "low risk" (n=44), "moderate risk" (n=16), "high risk" (n=40) and "severe risk" (n=30) protocols, according to the Peruggia guidelines. We calculated the total theoretical consensus-guided costs for anti-emetic treatment to be 2079.04 Deutsche Marks (DM) and the real costs to be 2024.93 DM (hospital supplier prices). CONCLUSION: In conclusion, we found a considerable drug-group-related difference between consensus guidelines for anti-emetic strategies and clinical practice. However, the total expenditures did not vary significantly. We assume, that the differences observed are due to patient-related factors like history of nausea and emesis, tumor stage, tumor location, sex, age, co-morbidity and alcohol consumption rather than to chemotherapy. A computer-assisted anti-emetic decision model (Emeto-Help) will be presented, which includes both the drug-related emetogenic potential and the individual patient's risk.