Background Malnutrition is associated with poorer outcomes in hospitalized patients. However, in hip fracture patients, the associations between malnutrition and poorer outcomes are unclear because of the use of nonestablished nutrition assessment tools in previous studies that may have some degree of misclassification bias. Therefore, this review aims to determine (1) the prevalence of malnutrition diagnosed in hospitalized hip fracture patients using established nutrition assessment tools and (2) the outcomes associated with malnutrition given some of the nonestablished nutrition assessment tools used in previous studies. Methods Four electronic databases were used. Studies that used established nutrition assessment tools to diagnose malnutrition in hip fracture patients within 48 h of hospital admission were included. Results Nine studies were included (n = 1665). Patients’ mean age ranged from 79.9 to 86.1 years. Eight studies reported the frequencies of each sex, and for females, it ranged from 70% to 81.8%. The prevalence of malnutrition was 4.0% to 39.4%. Malnutrition was independently associated with (1) increased mortality and (2) functional dependence. There was also a trend towards more supported living arrangements and impaired mobility in the longer term. Malnutrition was not associated with (1) hospital length of stay, (2) hospital readmissions, and (3) incidence of complications. Conclusion The prevalence of malnutrition in hip fracture patients is highly variable and is associated with poorer outcomes. Therefore, identifying malnourished hip fracture patients using established nutrition assessment tools is important, and adequate resources can be allocated to prevent malnutrition through early screening and intervention.