We previously have shown that the highly conserved eight-protein exocyst trafficking complex is required for ciliogenesis in kidney tubule cells. We hypothesized here that ciliogenic programs are conserved across organs and species. To determine whether renal primary ciliogenic programs are conserved in the eye, and to characterize the function and mechanisms by which the exocyst regulates eye development in zebrafish, we focused on , a central component of the exocyst complex, by analyzing both zebrafish mutants, and photoreceptor-specific Exoc5 knock-out mice. Two separate mutant zebrafish lines phenocopied morphants and, strikingly, exhibited a virtual absence of photoreceptors, along with abnormal retinal development and cell death. Because the zebrafish mutant was a global knockout, we also observed defects in several ciliated organs, including the brain (hydrocephalus), heart (cardiac edema), and kidney (disordered and shorter cilia). knockout increased phosphorylation of the regulatory protein Mob1, consistent with Hippo pathway activation. mutant zebrafish rescue with human EXOC5 mRNA completely reversed the mutant phenotype. We accomplished photoreceptor-specific knockout of Exoc5 with our fl/fl mouse line crossed with a rhodopsin-Cre driver line. In photoreceptor-specific knock-out mice, the photoreceptor outer segment structure was severely impaired at 4 weeks of age, although a full-field electroretinogram indicated a visual response was still present. However, by 6 weeks, visual responses were eliminated. In summary, we show that ciliogenesis programs are conserved in the kidneys and eyes of zebrafish and mice and that the exocyst is necessary for photoreceptor ciliogenesis and retinal development, most likely by trafficking cilia and outer-segment proteins.