Introduction: The natural course of adenomas of the ciliary-body epithelium (ACE) is uncertain, due to their low incidence and their frequent initial surgical management. Their differential diagnosis with amelanotic melanoma or metastasis is challenging and diagnostic biopsies require sufficient tissue and highly specialized pathologists. Ultrasound biomicroscopy offers high resolution images and clear sonographic signs suggestive of ACE allowing a more precise differential diagnosis and therefore, a more conservative initial attitude. Methods: Descriptive, retrospective, non-comparative study of consecutive cases of ACE observed between October 2003 and December 2019 in a reference unit in ocular oncology of a tertiary hospital. Patients were studied on a quarterly basis the first year and, subsequently, every 6 months with a complete ophthalmological exam and ultrasound biomicroscopy with the platform Aviso linear scanning 50 MHz probe (Quantel Medical, Clermont-Ferrand, France). Results: Three ACE were analysed for a median of 3 years (interquartile range: 2.5–5.5 years). Clinical features include a whitish-to-brown spherical mass, with engorged superficial vessels. Ultrasound biomicroscopy shows an oval-spherical shape, medium-to-high echogenicity, low acoustic attenuation, regular internal structure, and respect for the neighboring structures. By their clinical-ultrasonographic characteristics, one was considered an adenoma of the pigmented ciliary-body epithelium (browner and hyperechogenic) and two were classified as adenomas of the non-pigmented ciliary epithelium (whitish appearance and medium-echogenicity). Conclusion: Ultrasound biomicroscopy allows a reasonable clinicalsonographic suspicion of ACE. An initial conservative management is proposed as a safer option for stable, mildly symptomatic patients, avoiding aggressive sight threatening treatments.