BACKGROUND/PURPOSE: Posterior microphthalmos is a rare ocular condition characterized by a disproportionately small posterior segment and multiple retinal abnormalities. The diagnosis can be challenging, and novel findings on optical coherence tomography (OCT) angiography may help to identify this unusual disorder. The purpose of this study is to report OCT and OCT angiography findings in two siblings with posterior microphthalmos. METHODS: Case series at an academic eye institute including two affected siblings with posterior microphthalmos. RESULTS: The results of OCT testing in two siblings with posterior microphthalmos illustrated bilateral papillomacular retinal fold and loss of the foveal depression. Optical coherence tomography angiography findings included loss of the foveal avascular zone and complete vascularization across the fovea. CONCLUSION: Unique OCT angiography findings in posterior microphthalmos are described herein. These findings may support the diagnosis of posterior microphthalmos and aid in the understanding of the pathogenesis of this disease.