BackgroundStudies investigating the nutritional status of patients with leprosy and plantar ulcers are sparse. Therefore, the objective of this study was to describe the protein profile of leprosy patients with plantar ulcers from the Eastern Amazon region.MethodsA case record form was created for 75 patients with leprosy (31 with plantar ulcers and 44 without plantar ulcers) with the following data: sociodemographic characteristics, clinical form of leprosy, presence or absence of plantar ulcers, and nutritional assessment using anthropometry consisting of the measurement of body mass index, arm circumference, arm muscle circumference, and triceps skinfold. Levels of blood albumin, transferrin, and C-reactive protein (CRP) were also measured. Data regarding protein intake were obtained using a Food Frequency Questionnaire.ResultsPlantar ulcers occurred more frequently in male patients (67.7%), patients aged 40–49 years (mean ± SD: 47.3 ± 8.0 years), and patients receiving 300 or 600 USD (71.0%). The mean weight and height of patients were 71.6 ± 11.4 kg and 1.62 ± 0.1 m, respectively. High levels of CRP were detected in 51.6% of leprosy patients with plantar ulcers and only 9.1% of patients without plantar ulcers (P < 0.001). Nutritional depletion of transferrin was observed in 14.3% of patients with paucibacillary leprosy and 44.3% of patients with multibacillary leprosy (P = 0.0447). Most patients had normal levels of serum albumin (74.2% with plantar ulcers and 77.3% without plantar ulcers).ConclusionsMost leprosy patients with plantar ulcers have normal levels of serum albumin and transferrin and high CRP levels, which indicates the presence of an inflammatory process. Our findings suggest the need to monitor patients with leprosy to prevent the occurrence of plantar ulcers and to provide adequate treatment for patients with existing plantar ulcers.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-017-0318-y) contains supplementary material, which is available to authorized users.