Leprosy will continue to be a public health problem for several decades. The World Health Organization (WHO) recommends that, for treatment purposes, leprosy cases be classified as either paucibacillary or multibacillary (MB). A uniform leprosy treatment regimen would simplify treatment and halve the treatment duration for MB patients. The clinical trial for uniform multidrug therapy (U-MDT) for leprosy patients (LPs) in Brazil is a randomised, open-label clinical trial to evaluate if the effectiveness of U-MDT for leprosy equals the regular regimen, to determine the acceptability of the U-MDT regimen and to identify the prognostic factors. This paper details the clinical trial methodology and patient enrolment data. The study enrolled 858 patients at two centres and 78.4% of participants were classified as MB according to the WHO criteria. The main difficulty in evaluating a new leprosy treatment regimen is that no reliable data are available for the current treatment regimen. Relapse, reaction and impaired nerve function rates have never been systematically determined, although reaction and impaired nerve function are the two major causes of nerve damage that lead to impairments and disabilities in LPs. Our study was designed to overcome the need for reliable data about the current treatment and to compare its efficacy with that of a uniform regimen.