Real-time quantitative polymerase chain reaction (qRT-PCR) has emerged as a powerful and popular tool for quantitating differences in transcriptional gene expression levels between samples. Validation of the stability of reference genes is a fundamental step before initiating qRT-PCR assays. Sparassis latifolia is an edible and medicinal fungus containing a remarkably high concentration of β-glucan, which has many biological and pharmacologic activities. S. latifolia may be a model species for studying fungal photobiology because its fruiting body formation requires more light than other fungi. However, suitable reference genes for qRT-PCR have not yet been determined. In the present study, 10 candidate reference genes in S. latifolia were evaluated and validated under different developmental stages and light conditions. To evaluate the suitability of candidate reference genes, three popular software programs (geNorm, NormFinder, and BestKeeper), along with the delta Ct method, were used to analyze these genes; the final ranking was determined using RefFinder. According to our results, Actin and GAPDH were expressed at the most stable levels under different developmental stages and light conditions.