In this nationwide cohort study, we investigated trends in hip fracture incidence, hospital length of stay (LOS), and 30-day mortality after admission in Sweden. The cohort included all individuals in Sweden aged ≥ 50 years with a first hip fracture diagnosis during 1998–2017 (N = 313,761). The outcomes were hip fracture incidence and 30-day mortality. The results showed that the incidence of hip fracture decreased from 79.2 to 46.7/10,000 population in women and from 35.7 to 26.5/10,000 population in men. In contrast, 30-day mortality increased from 4.3% to 6.2% in women (P < 0.001) and from 8.4% to 11.1% in men (P < 0.001). Strong risk factors (P < 1 × 10–25 for all) for 30-day mortality were older age, male sex, and shorter LOS. From 1998 to 2017, LOS decreased by on average 4 days and was shorter in both male and female aged ≥ 90 years compared to those aged 80–89 (P < 0.001 for comparisons). In conclusion, despite population aging, hip fracture incidence in Sweden has decreased over the last 20 years. However, short-term mortality has increased, which to some extent may partly be explained by the fact that LOS has decreased without being adapted to important risk factors.