Highly parallel genotyping assays, such as the GoldenGate assay developed by Illumina, capable of interrogating up to 3,072 single nucleotide polymorphisms (SNPs) simultaneously, have greatly facilitated genome-wide studies, particularly for crops with large and complex genome structures. In this report, we provide detailed information and guidelines regarding genomic DNA preparation, SNP assay design, SNP assay protocols, and genotype calling using Illumina's GenomeStudio software.