Background and Purposes The objectives of this study were to investigate the inter- and intraobserver agreement in the classification of distal radius fractures (DRFs) according to the AO and the Buttazzoni classification system, for the two different radiology modalities: conventional radiography (CR) and cone-beam computed tomography (CBCT). Furthermore, we aimed to explore whether the radiological modality used influences the choice of treatment. Patients and Methods Fifty consecutive patients with DRFs were included. The fractures were visualized by both CR and CBCT. All images were independently reviewed by five observers (three orthopaedic surgeons and two radiologists) and the fractures were classified according to the AO and the Buttazzoni classification. Agreement on fracture classification between CR and CBCT, interobserver agreement for all observers, and intraobserver agreement for a repeated assessment after 8 weeks were calculated. Treatment was suggested by the orthopaedic surgeons. Results The Buttazzoni classification showed higher interobserver agreement than the AO classification, but the agreement for the AO classification was increased using CBCT. The agreement between classification of fractures by CR and CBCT for each observer varied from fair to moderate. CBCT was superior for classification of dorsally comminute fractures using both the AO and the Buttazzoni system. In 38% ( n = 57) of the observations, the suggested treatment was changed when CBCT was used, both from less advanced to more advanced and vice versa. Conclusion The choice of radiological modality affects both the classification and the choice of treatment for DRFs and CR tends to underestimate the complexity of DRFs. Level of Evidence Level 1.