Background <p>Distal radius fractures (DRFs) are usually considered low-risk injuries. However, data on serious adverse events (SAE) and mortality in large population-based cohorts of non-surgically treated DRFs are limited. We aimed to examine 30-day risk of SAEs with associated factors and mortality up to one year after non-surgical treatment of DRFs.</p> Methods <p>This is a retrospective population-based cohort study using the Danish National Patient Registry. All adults (≥ 18 years) with a first-time, non-surgically treated DRF between 1998 and 2018 were included. SAEs (stroke, myocardial infarction, pulmonary embolism, respiratory tract infection, acute renal failure) within 30 days and mortality up to 1-year post-fracture were assessed. Association between age, sex, cancer, and major osteoporotic fractures (MoF) and the occurrence of SAEs and mortality were analyzed.</p> Results <p>A total of 184,446 non-surgically treated DRFs were identified, with median age of 64 years. SAEs were generally uncommon. Death was the most frequent but occurred in only 0.7% of patients within 30 days. Male sex, concurrent MoF, and cancer were significantly associated with a higher risk of SAEs and death. Patients with concurrent MoF had a 5-fold increased risk of 30-day mortality (OR 5.3, CI 4.6–6.2).</p> Conclusion <p>Short-term SAEs were rare after non-surgical treatment for DRF. The presence of concurrent MoF in nonoperatively treated patients with DRF is associated with an elevated risk of early SAEs and death. These findings suggest the need for increased clinical attention in selected high-risk subgroups.</p> Trial registration <p>Not applicable, this study is an observational retrospective cohort; no prospective registration was required.</p>