Purpose: Excess mortality among hip fracture patients is well documented. Less is known, however, about the causes of death in this group of patients, although existing literature suggests that bronchopneumonia and cardiovascular diseases constitute the leading causes of death. In this study, we investigated the causes of death in Danish hip fracture patients, who died within 30-days after sustaining a hip fracture, with a focus on differences in causes of death between men and women and between different age groups. Furthermore, the frequency of potentially preventable causes of death such as pneumonia, urinary tract infections and thromboembolic events was examined. Methods: All Danish patients aged 18 or more suffering from a hip fracture in the period 2002–2012 were examined for inclusion into the study. Data were collected from the Danish National Patient registry. The last month of 2012 being December was left out since we were looking at 30-days mortality. Logistic regression analysis was used to test the association between 30-day mortality with each of the causes of death adjusted for age, sex and CCI in multivariable models with results presented as odds ratios (OR) with 95% confidence intervals. Results: During this period, 93,637 patients sustained a hip fracture. Of these, 9504 patients died within 30-days and were included in the study. For patients dead within 30-days after sustaining a hip fracture, the two leading medical causes of death were cardiovascular disease (21.1%) and pneumonia (10.5%) when looking at both genders. A frequent cause of death especially in the younger age group of women less than 50 years old were infections (other than pneumonia) (18.2%) especially urinary tract infections. Pulmonary embolism accounted for 3.9% of causes of deaths in hip fracture patients. Conclusion: In this study, cardiovascular disease and pneumonia were overall the leading medical causes of death in patients dead within 30-days after sustaining a hip fracture. Apart from pneumonia, another potentially preventable infection in younger female hip fracture patients was urinary tract infections. Pulmonary embolism, another potentially preventable cause of death might be underreported in Danish death certificates.