This article describes the methodology of the validation about the identification of total mercury in blood samples by Zeeman atomic absorption spectrophotometry RA-915+ with the module of Pyrolysis PYRO-915+, suitable for the direct determination of total mercury concentrations in various matrices, that unlike other atomization techniques (graphite furnace, cold vapor or hydride generator) does not require a sample pre-treatment. With the application of this validation,is provided the reliability in the results. Most of the validation parameters were subjected to analysis of variance ANOVA with a confidence level of 95%. It was obtained a detection limit of 2.16 ug/L, a quantitation limit of 5.54ug/L and linearity in the range of 5.54 ug/L to , in addition, the precision and accuracy was evaluated, obtaining favorable results in the analysis. The calculation of the expanded uncertainty for this method was 0.610 ug/L.