To quantify serum butyrylcholinesterase activity in haemodialysis patients and to evaluate if the homocysteine levels and/or oxidative stress biomarkers have an effect on butyrylcholinesterase.Blood samples were collected from patients and healthy subjects (control). The plasma homocysteine and TBARS levels; serum butyrylcholinesterase activity; blood δ aminolevulinic acid dehydratase (ALA-D) activity and methahaemoglobin were analyzed. The mortality of the patients was also evaluated after 3 years.The homocysteine was increased and butyrylcholinesterase decreased compared to control (p<0.05). TBARS and methahaemoglobin were increased and ALA-D decreased (p<0.05). The following correlations were found: homocysteine with butyrylcholinesterase (−0.44); methahaemoglobin (0.41); ALA-D (−0.68); and TBARS (0.66). The partial correlation between homocysteine with butyrylcholinesterase, withdrawn the effect of TBARS, was −0.30; all p<0.05. Moreover, it was observed that 22% of the patients died due to cardiovascular problems.Thus, our findings support a direct association between the reduction of butyrylcholinesterase by the increase of homocysteine and an indirect effect by increase in oxidative stress.