The aim of our investigation was to determine the concentrations of Cu, Zn, and Cr in urine samples under routine clinical laboratory conditions. To asses the reliability of these methods, critical factors such as detection limit(s), calibration range(s), cost, accuracy, and precision were studied. Our method was employed for the quantitative determination of zinc, chromium, and copper in urine samples from steel production and quality control (QC) workers and healthy unexposed controls. After pretreatment with acids, the samples were digested via a microwave oven. Zinc was determined by flame absorption spectrophotometry (FAAS), whereas chromium and copper were determined by a graphite-furnace atomic absorption spectrophotometry (GFAAS). Our results indicate that urinary zinc, chromium, and copper levels of the exposed workers are significantly higher than those of the controls. The possibility that these metals are involved in the etiology of diseases is discussed and recommendations are made to improve workplace ventilation and industrial hygiene practices.