Cone-beam computed tomography (CBCT) has expanded from dento-maxillofacial radiology to otorhinolaryngology, being proposed as a low-dose alternative to multidetector computed tomography (MDCT) for evaluating uncomplicated sinonasal disease and for surgical planning. Major guidelines (EPOS, ICAR-RS, ACR) recommend native high-resolution CT for bone and MRI for loco- regional complications, while the role of CBCT remains focused on bone anatomy and the oro-sinusal interface. The objective of this review was to systematically synthesize the evidence on the diagnostic performance, radiation dose, indications/contraindications, and limitations of CBCT in sinonasal pathology, and to propose a practical algorithm for its use. The methodology consisted of searching PubMed/Medline and “gray” literature (professional society positions, guidelines) until September 2025; relevant guidelines/consensuses and original/comparative studies reporting the utility of CBCT for rhinosinusitis (acute/chronic), odontogenic sinusitis, fungal pathology, anatomical variations, pre- and intraoperative planning, doses/technical parameters were included. Papers focused exclusively on non-sinonasal pathology or on contrast-enhanced CBCT were excluded. The synthesis is narrative, oriented towards clinical questions. The key results were: (1) CBCT provides an excellent representation of the bone anatomy of the osteomeatal complex, with superior spatial resolution to MDCT, but with clearly inferior tissue contrast (limiting the evaluation of complications, soft tissues, and perisinusal extension); (2) the effective dose of CBCT for sinuses typically varies ~0.05–0.48 mSv depending on the protocol/FOV, usually below conventional MDCT, but not consistently below ultra-low-dose MDCT or photon- counting CT (PCCT) protocols, which can achieve even lower doses with superior image quality; (3) tor uncomplicated chronic rhinosinusitis (CRS), CBCT correlates well with endoscopy and is adequate for scoring (e.g., LM analog), assessing anatomical variations, and planning FESS; for orbital/intracranial complications, suspected tumors, or invasive fungal rhinosinusitis, CBCT does not replace CT/MRI; (4) In odontogenic sinusitis (ODS), CBCT is the first-line investigation because it finely delineates dental pathology, oro-antral defects, and foreign bodies, and consensus recommendations support its use guided by indications; (5) Intrinsic limitations: poor tissue contrast, uncalibrated/unreliable HU values, metal artifacts, and sometimes restrictive FOV; (6) In the clinical setting, “point-of-care” CBCT shortens the diagnostic pathway and can reduce costs/delays, but careful case selection and adherence to the justification principle are essential. In conclusion, CBCT has robust diagnostic value for uncomplicated rhinosinusal disease and for the dento-sinusal interface, with the advantage of dose and access, but it does not substitute MDCT/MRI in risk/complication scenarios. Responsible implementation, according to guidelines and radioprotection principles, maximizes benefits and minimizes risks.