The aim of the work was to compare two analytical methods of trace analysis in respect to their applicability in heavy metals determination in biological samples. Atomic absorption spectrometry (AAS) may be considered as the method of choice in such analyses due to its accuracy, precision and low detection limit. On the other hand, voltammetric methods seem to be as useful, but rarely applied. Having in mind that there is no universal analytical method, we have compared two AAS and voltammetric methods as the tools for Zn and Cu determination in the samples collected from rat gastric juice and gastric mucosa. Construction of the renewable silver amalgam film electrode (Hg(Ag)FE) for stripping voltammetry was described. Detailed optimization of measurements procedure and sample preparation for differential pulse anodic stripping voltammetry (DP ASV) and AAS were also performed and presented. The obtained results of quantitative analysis of the chosen parameters by means of both methods are discussed