Copy-number variation (CNV) in particular genomic segments owing to deletions or duplications can induce changes in cellular gene expression patterns and may increase susceptibility to diseases such as cancer. The aim of this study was to examine CNVs related to the incidence of epithelial ovarian cancer in chickens. Genomic DNA was extracted from blood cells and cancerous ovaries collected from four 120-week-old White Leghorn chickens and were used for array-based comparative genome hybridization (CGH) analysis. As a result, 25 amplified and 10 deleted CNV regions were detected in chicken ovarian cancer. Of these, 10 amplified and two deleted CNV regions contained genes associated with human ovarian cancer. Our study using a chicken model may provide a better understanding of human epithelial ovarian cancer.