This study was undertaken to investigate the copper and zinc levels of hydatid cyst fluids in liver, lung, and spleen of infected cattle and sheep in the Malatya region. The copper and zinc values were determined by atomic absorption spectrophotometry. Copper average levels of hydatid cyst fluids in liver, lung and spleen of cattle were found to be 1.944 +/- 0.372 mu g/dL, 1.272 +/- 0.469 mu g/dL and 2.234 +/- 0.932 mu g/dL, respectively, and that of zinc 0.312 +/- 0.147 mu g/dL, 1.112 +/- 1.035 mu g/dL and 0.886 +/- 0.405 mu g/dL. Average copper levels of hydatid cyst fluids in liver and lung of sheep were found to be 2.542 +/- 0.352 mu g/dL and 1.552 +/- 0.558 mu g/dL, respectively, whereas those of zinc were found to be 0.747 +/- 0.151 mu g/dL and 1.220 +/- 0.379 mu g/dL. Copper and zinc levels of hydatid cyst fluid were higher in sheep organs than in corresponding cattle organs.