In this study, the performance of a hazelnut husker design, which is widely used in Turkey, was investigated. Ten huskers from ten different orchards were studied. Results showed that nut output varied between 1170 and 2085 kg h(-1). Filled-nut husking efficiency, blank-nut separation efficiency, kernel losses, damaged-nut ratio and husk-separation efficiency varied between 95.70% and 99.50%, 28.60% and 96.60%, 0.10% and 2.78%, 0% and 3.49% and 96.69% and 99.32%, respectively. It was found that variations in performance characteristics of the machines predominantly resulted from the differences in the characteristics of hazelnuts and the different adjustments performed on separation systems of the machines. The main problem associated with obtaining optimum performance concerned the design of the upper and lower separation systems. (C) 2008 IAgrE. Published by Elsevier Ltd. All rights reserved.