Objectives: to develop a cost-effectiveness analysis of one-piece drainable pouch (OPDP) versus two-piece drainable pouch (TPDP) for colostomates under the perspective of patient’s out-of-pocket expenses in Rio de Janeiro, Brazil. Methods: data was collected from the prescriptions used for the colostomy pouch change and based on the best practices for the care and prevention of injuries in peristomal skin, according to the domiciliary visits from a stomotherapy service during the year 2014. Materials for the periestomal skin care and wound/dermatitis prevention were considered (US$ currency rate = R$3,20). Results: the drainable pouch represented 36.3%(US$285.0) of the costs per patient/month for the OPDP and 54.3% (US$212.5) for the TPDP. However, costs related to the inputs needed for each pouch change (eg. adhesive removers, skin protective) represent 63.7% for the OPDP and 45.7% for the TPDP. Total costs with the OPDP was US$784.42 and US$391.06 for the TPDP drainable pouch, showing a cost-saving profile if the TPDP was chosen as the standard care (incremental –US$393.37). Conclusions: based on the patient’s outcomes, the best practices regarding the periostomal skincare, the patient’s preferences and costs, the adoption of the two-piece drainable pouch for colostomates shows to be cost-effective when compared to the one-piece drainable pouch. Further studies regarding the colostomate’s quality of life are needed