The economic burden of Buruli ulcer for patients has not been well-documented. This study assessed the costs of Buruli ulcer care to patients from the onset of illness to diagnosis and to the end of treatment. This was a cross-sectional cost of illness study conducted among patients with Buruli ulcer in four States in Nigeria between July and September 2015. A structured questionnaire was used to collect data on the patients' characteristics, household income and out-of-pocket costs of care. Of 92 patients surveyed, 54 (59%) were older than 15years, 49 (53%) were males, and 86 (93%) resided in a rural area. The median (IQR) direct medical and non-medical cost per patient was US$124 (50-282) and US$3 (3-6); corresponding to 149% and 4% of the patients' median monthly household income, respectively. The overall direct costs per patient was US$135 (58-327), which corresponded to 162% of median monthly household income, with pre-diagnosis costs accounting for 94.8% of the total costs. The direct costs of Buruli ulcer care were catastrophic for 50% of all patients/households - the rates of catastrophic costs for Buruli ulcer care was 66% and 19% for patients belonging to the lowest and highest income quartiles, respectively. Direct costs of Buruli ulcer diagnosis and treatment are catastrophic to a substantial proportion of patients and their families.