Purpose: The frequency of total hip arthroplasty (THA) has increased significantly. The morbidity and economic burden of periprosthetic hip fractures (PPHFx) following THA is high. The objective of this study is to identify predictors of in-hospital mortality, length of stay (LOS), and hospital costs associated with PPHFx. Materials and Methods: A retrospective analysis of the National Inpatient Sample (NIS) for all patients diagnosed with periprosthetic fracture around the internal prosthetic hip joint (International Classification of Disease, Tenth Revision, Clinical Modification [ICD-10-CM], M97.01XA, and M97.02XA) between 2016 and 2019 was conducted. Predictors of outcomes following PPHFx were assessed using univariable analyses; those with a P-value below 0.2 were included in the final multivariable models. Logistic regression was used to determine predictors of in-hospital mortality and linear regression for assessment of hospital cost and LOS predictors. Results: The study included 77,565 patient encounters. Significant predictors of in-hospital mortality included age, female sex, and comorbidities, such as metastatic cancer and liver disease. Predictors of increased LOS included black race, comorbidities, such as paralysis and fluid and electrolyte disorders, primary payment source, household income, hospital size, and type. Hospital costs showed an association with race, comorbidities, hospital type, and procedure. Conclusion In the setting of PPHFx, higher comorbidity, particularly fluid and electrolyte, paralysis, and metastatic cancer, showed an association with all three outcome variables. In addition to comorbidity, advanced age, particularly nonagenarians, showed an association with in-hospital mortality, while cost was primarily driven by the procedure performed.