Although the incidence of proximal femur fractures (PFFs) is increasing, few detailed reports on associated long-term outcomes and causes of death exist. We aimed to evaluate long-term outcomes and causes of death ≥5 years after surgical treatment of PFFs. This retrospective study included 123 patients (18 males, 105 females) with PFFs treated at our hospital between January 2014 and December 2016. Cases (median age: 90 [range, 65–106] years) comprised 38 femoral neck fractures (FNFs) and 85 intertrochanteric fractures (IFs). Surgical procedures included bipolar head arthroplasty (n = 35), screw fixation (n = 3), and internal fixation with nails (n = 85). The mean post-surgical follow-up time was 58.9 (range, 1–106) months. Surveyed items included survival (1 vs 5 years; sex; age, >90 vs <90 years; IF vs FNF), comorbidities, waiting time after the injury (died vs survived), operative time (proximal femoral nail antirotations [PFNA] vs FNF, died vs Survived), blood loss (PFNA vs FNF; died vs survived), and cause of death (IF vs FNF; <1 vs >1 year). Among all patients, 83.7% had comorbidities (IF, 90.5%; FNF, 81.5%). Among patients who died and survived, 89.1% and 80.5% had comorbidities, respectively. The most common comorbidities were cardiac (n = 22), renal (n = 10), brain (n = 8), and pulmonary (n = 4) diseases. Overall survival (OS) rates at 1 and 5 years were 88.9% and 66.7%, respectively. Male/female OS rates were 88.8%/88.3% and 66.6%/66.6% (P= .89) at 1 and 5 years, respectively. OS rates for the <90/≥90 age groups were 90.1%/76.7% and 75.3%/53.4 (P< .01) at 1 and 5 years, respectively. The 1- and 5-year OS (IF/FNF) rates were 85.7%/88.8% and 60%/81.5%, respectively; patients with IFs had significantly lower OS than those with FNFs at both timepoints (P= .015). There was a marked difference in the operative time between died (43.5 ± 24.0: mean ± S.D.) and survived (60 ± 24.4: mean ± S.D.) patients. The main causes of death were senility (n = 10), aspiration pneumonia (n = 9), bronchopneumonia (n = 6), worsening heart failure (n = 5), acute myocardial infarction (n = 4), and abdominal aortic aneurysm (n = 4). Overall, 30.4% of the cases were related to comorbidities and related causes (e.g., hypertension-related ruptured large abdominal aneurysm). Managing comorbidities may improve long-term postoperative outcomes of PFF treatment.