OBJECTIVES: To evaluate the impact on costs of treating complications derived from chronic kidney disease (CKD) in patients undergoing hemodialysis in the public healthcare system in Brazil. METHODS: Owing to the lack of local databases, a survey with experts was conducted to collect data about the main causes of hospital admissions which resulted from complications during the dialysis period of CKD patients. A group of 600 patients from reference centers in Brazil was studied. Later, the experts answered to a questionnaire about the procedures needed to manage complications. Then, a micro-costing was performed, only direct costs were considered: length of staying, medical procedures, physician fees and drugs.  Sources used for costing were: SAI/SIH – SUS (the government reimbursement procedures list), Revista Kairos (January 2009) (drugs price list) and Guia Farmacêutico Brasíndice (January 2009) (materials price list). The time horizon of this analysis was 1 year, thus no discount rate was assumed. The perspective assumed was that of the public payer. RESULTS: The 3 most frequent causes of hospital admissions and their respective costs in the studied centers were: cardiac complications (33.27%; R$2789); infections (31.90%; R$3113); and venous access complications (9.20%; R$2183). For an average patient, the total costs in 1 year of treatment were estimated to be R$4358. CONCLUSIONS: This study suggests that for the 600 patients studied group the economic impact for the public payer with hospital admissions caused by CKD complications is significant being as high as R$ 2,615,331 in one year.