The levels of xenobiotics and trace elements in human breast cancer tissues and adjacent normal tissues were examined in 50 breast cancer patients. Cadmium, lead, zinc, copper and magnesium levels were determined by voltammetric (ASV) and spectrophotometric (AAS) methods. The study demonstrated that samples taken from the central regions of cancer generally had different concentration levels of xenobiotics and trace elements than normal tissues. The levels of lead, cadmium and zinc, copper and magnesium were all significantly higher in cancerous tissues as compared to the unaffected cells. Strong, statistically significant positive correlations between xenobiotics and trace elements were found, both in cancerous and healthy tissues. It was also noted that correlations in cancer tissues were more significant than those within normal tissues.