The aim of this study was to evaluate the toxicity and efficacy of combination chemotherapy with weekly 24-h continuous infusion of 5-fluorouracil (5-FU)/folinic acid, weekly paclitaxel and 3-weekly cisplatin in patients with unresectable, locally advanced or metastatic gastric adenocarcinoma. Between November 1999 and November 2001, 29 chemotherapy-naive patients (13 male and 16 female) with a median age of 56 years (range 22-72) were consecutively enrolled at three centers. 5-FU 2 g/m2 was given weekly over 24 h i.v. preceded by folinic acid 500 mg/m2 as a 2-h infusion. Paclitaxel 80 mg/m2 was administered as a 1-h infusion weekly and cisplatin 50 mg/m2 as 1-h infusion on days 8 and 29. Six weeks of therapy (days 1, 8, 15, 22, 29 and 36) followed by 1 week of rest was considered one cycle. A median of 3 cycles (range 1-5) was administered to 29 patients with a total of 73 cycles applied. All patients were assessable for toxicity and survival, 28 patients were assessable for response (one patient received less than one complete cycle and could not be evaluated for response). Four patients (14%) obtained a complete response and 10 patients (34%) a partial response (overall response rate 48%, 95% CI 29-68%). Seven patients (24%) had stable disease. Seven patients (24%) had progressive disease during or within 4 weeks after treatment. The median progression-free and overall survival times were 8 months (range 1-23) and 11 months (range 1-23), respectively. Overall toxicity was acceptable. Hematological toxicity was favorable with only one patient (3%) experiencing WHO grade 3/4 leukocytopenia and one patient (3%) WHO grade 3/4 anemia. Non-hematologic WHO grade 3/4 toxicities included alopecia in 19 (66%), nausea/vomiting in six (21%), diarrhea in six (21%), neurotoxicity grade 3 in three (10%) and infection in three (10%) patients. A total of 42 applications (10%) (range 0-5) had to be postponed and dose reductions of at least one drug was necessary in 37% of applications. In three patients (10%) treatment was stopped because of toxicity. All patients were treated on an outpatient basis. Thus, the combination of weekly paclitaxel, cisplatin and continuously infused 5-FU/folinic acid appears to be a highly active regimen for the treatment of patients with advanced gastric cancer. Compared with our previous experience with the same combination of drugs but using paclitaxel at 175 mg/m2 given every 3 weeks, the protocol with weekly application of paclitaxel 80 mg/m2 shows a reduced incidence of hematologic toxicity, particularly leukopenia. Other organ toxicities apart from a slightly higher incidence of peripheral neuropathy were comparable between the two treatment protocols. Efficacy with a response rate of 50% was well preserved by this weekly regimen.