Arsenic and cadmium are toxic metals of environmental significance with harmful effects on man. To study the toxicological and biochemical effects of arsenic/cadmium in mammals a combined metallomic and metabolomic approach has been developed, complemented with the measurement of biochemical parameters in blood and histopathological evaluation of liver injury in mice Mus musculus under exposure to both xenobiotics. Size-exclusion chromatography (SEC) was combined with affinity chromatography (AF) and ICP-MS detection using species unspecific isotopic dilution analysis (SUID) to characterize the biological effects of As/Cd on selenium containing proteins in the bloodstream of exposed mice. On the other hand, both direct infusion mass spectrometry (DIMS) and gas chromatography-mass spectrometry (GC-MS) provided information about changes in metabolites caused by metals. The results show that As/Cd exposure produces interactions in the distribution of both toxics between organs and plasma of mice and antagonistic interactions with selenium containing proteins in the bloodstream. Interplay with essential metabolic pathways, such as energy metabolism and breakdown of membrane phospholipids were observed, which are more pronounced under As/Cd exposure. In addition, heavy metal and metalloid causes differential liver injury, manifested by steatosis (non-alcoholic fatty liver disease, NAFLD) and infiltration of blood cells into the space of Disse.