Introduction <p>The number of individuals aged &gt; 90 years (super-old) is steadily increasing, along with the incidence of femoral neck fractures. Surgical treatment in patients aged &gt; 85 years is associated with a high risk of complications, and in super-old patients, surgical intervention is particularly challenging because of multiple comorbidities. However, data on mortality without surgery and its associated factors in this age group are lacking. This study aimed to (1) evaluate the 6-month mortality rate following femoral neck fractures in super-old patients and (2) identify factors associated with 6-month mortality following injury.</p> Materials and methods <p>This retrospective study included patients aged &gt; 90 years admitted to our hospital with femoral neck fractures between April 2010 and March 2021, with at least 6 months of follow-up. We collected data on demographics, fracture type, preinjury ambulatory function, treatment type (surgical or non-surgical), and admission laboratory data. Patients were grouped by survival status at 6 months after injury, and mortality rates and associated predictive factors were analyzed.</p> Results <p>A total of 76 patients were included in the study (non-surgical group, <i>n</i> = 37; surgical group, <i>n</i> = 39). The cohort included 14 men and 62 women, with a mean age of 91.9 years (range, 90–96 years). The overall 6-month mortality rate was 21.0% (16/76), with higher mortality in the non-surgical group (40.5%) than in the surgical group (2.5%). Significant predictors of 6-month mortality were pre-injury ambulatory function and serum albumin levels at admission.</p> Conclusion <p>In super-old patients with femoral neck fractures, the 6-month mortality rate is approximately 20%, increasing to 40% in the absence of surgical treatment. Poor preinjury ambulatory function and low albumin levels were significant predictors of mortality. These findings highlight the importance of surgical treatment and pre-operative assessments in this population.</p>