<p>Although the quail is a species characterized by high disease resilience, few studies have investigated tissue immunity during developmental stages using microscopic analysis. The current study identified dendritic cell precursors in embryonic quail esophagus using transmission electron microscopy (TEM), scanning electron microscopy (SEM), histological staining, and immunohistochemistry. On day 8, dendritic cell precursors appeared in the undifferentiated primitive epithelium and the lamina propria. They were distinguished by characteristic dendritic cell granules, which had lamellar membrane infoldings. They had a scant amount of smooth endoplasmic reticulum (SER) and fewer granules than on days 15 and 17 of incubation. At these latter stages, the dendritic cell had distinctive SERs, vesicles, lysosomes, and granules. Different forms of granules were detected, including rounded lamellar granules, and both rod-shaped and the more typical tennis-racket-shaped Birbeck granules. By SEM, dendritic cells had large cell bodies and numerous processes. Embryonic dendritic cells also express CD21, CD34, CD68, and vascular endothelial growth factor (VEGF). In conclusion, dendritic cells were identified in both early and late stages of esophageal development in quail embryos. We suggested that they establish an immunological barrier in prenatal life that plays a critical role in digestive immunity in the quail.</p>