Our previous cDNA microarray study showed that the growth hormone (GH) gene may involve in the duck egg formation process. The purpose of this study was to investigate the relationship between GH genotypes of single nucleotide polymorphisms (SNPs) and reproductive traits of Tsaiya ducks. Primer pairs for the coding region in the GH were designed based on the duck genomic sequence. Polymorphisms were detected by polymerase chain reaction (PCR)-single strand polymorphism (SSCP) and were verified by DNA sequencing. Nineteen SNPs were identified in the duck GH gene, of which three coding SNPs (C3169T, C3700T and C5058G) were genotyped to investigate the associations with reproductive traits. The results showed that each SNP was associated with at least one duck fertility-related trait (p < 0.05). Haplotypes constructed on these three SNPs were associated with fertility rate (FR) and maximum duration of fertility (MDF) (p < 0.05). In particular, diplotype H1H1 was dominant for FR and MDF. This suggested that GH gene polymorphisms are associated with duck fertility-related traits. The SNPs in this gene may be used as potential markers for marker-assisted selection.