We investigated a sample of MDT-treated leprosy patients ascertained at the Dr. Marcello Candia Reference Unit in the Sanitary Dermatology of the State of Pará (UREMC) with the aim of identifying associations among CYP2E1 polymorphisms [including 1053 C>T, 1293G>C (CYP2E1*1A, CYP2E1*5); 7632T>A (CYP2E1*1A, CYP2E1*6); 96-bp INDEL CYP2E1*1C (DEL) and CYP2E1*1D (INS)] and GSTM1 polymorphisms (GSTM1*1 and GSTM1*0) and possible protection factors for leprosy patients. Here, GSTM1 is linked to leprosy.