OBJECTIVES: Cancer incidence has increased in last decades. Meanwhile, new and costly intravenous chemotherapy drugs (CT) are added to current treatment options. Cost of chemotherapy is not restricted to drugs themselves, and some of the equipment used for infusion can impact the final value. CT can be administered on simple IV lines although some require the use of pumps infusion sets (PIS) both of which may be PVC free or photosensitive depending on the drug. Nonetheless, several cancer centers in Brazil adopt CT pump infusion as a rule, despite manufacturers instructions. We aim to assess the added cost of unnecessary PIS use during CT infusion. METHODS: In this cost-minimization study we compared 2 scenarios: use of PIS according to manufacturer recommendations or as a rule for all CT. Chemotherapy treatments for breast cancer (AC-T, AC-TH, TAC, FAC, CMF and FEC100), lung cancer (carboplatin/paclitaxel with and without bevacizumab, vinorelbine/cisplatin, cisplatin/paclitaxel and pemetrexed/cisplatin) and colon cancer (fluorouracil/leucovorin, FOLFIRI, FOLFOX, cetuximab/irinotecan) were listed from the Brazilian Society of Clinical Oncology (SBOC) manual. Minimum, mean and maximal costs for drugs and equipment were retrieved from the official price list (SIMPRO), daily cost of infusion and increment in cost were also calculated in Brazilian Reais (R$). RESULTS: Fifteen CT combinations were evaluated (6 for breast, 5 for colon and 4 for lung cancer). For breast cancer, the mean incremental cost per day of infusion with PIS varied from R$ 994.35 to R$ 1,839.54, depending on the chemotherapy scheme used. For lung cancer these values varied from R$ 356.34 a R$ 1,201.53 and for colon cancer treatment the incremental cost was R$ 1,226.36. CONCLUSIONS: Although medications are the main source of expense in cancer treatment, unnecessary use of PIS can add considerable costs to chemotherapy and correct use according to manufacturer recommendation should be reinforced.