Abstract Background Hip fracture is a common condition among elderly and one of the leading causes of disability. Malnutrition is widely present in older patients and has been identified in several studies as an important and modifiable prognostic factor for several medical conditions, including hip fracture. The aim of the present study is to evaluate the association between malnutrition, assessed by validated tools, and selected health outcomes for different follow-up intervals from hip fracture, in particular: mortality, changes in mobility/living arrangements and postoperative delirium. Methods A literature search on PubMed, Web of Science and Scopus databases up to September 2023, was conducted to identify all studies involving older subjects that reported an association between MNA/GNRI/PNI/CONUT score and health outcome after hip fracture. Meta-analysis was performed by a random-effects model using risk values (RR/OR/HR) extracted from 14 eligible selected studies. Results Malnutrition significantly increased the risk of any adverse outcome by 70% at 1 month, and up to 250% at 1 year, showing an increasing trend with longer follow-up periods. One month after hip fracture, malnutrition significantly increased the risk of postoperative delirium by 275% (OR = 2.75; 95% CI 1.80-4.18; p ≤ 0.05), mortality by 342% (OR = 3.42; 95% CI 2.14-5.48; p ≤ 0.05) and mortality hazard risk by 351% (HR = 3.51; 95% CI 1.63-7.55; p ≤ 0.05). One year after hip fracture, malnutrition significantly increased the risk of transfer to more supported living arrangements by 218% (OR = 2.18; 95% CI 1.58-3.01; p ≤ 0.05), declined mobility by 41% (OR = 1.41; 95% CI 1.14-1.75; p ≤ 0.05), mortality by 368% (OR = 3.68; 95% CI 3.00-4.52; p ≤ 0.05) and mortality hazard risk by 234% (HR = 2.34; 95% CI 1.91-2.87; p ≤ 0.05). Conclusions These findings underscore that malnutrition worsens outcomes after hip fracture in elderly, emphasizing the importance of nutritional assessment to mitigate potential adverse consequences. Key messages • The results of the present study underscore that malnutrition increases the risk of death and worsens mobility and independence after hip fracture in older adults. • Routine nutritional status evaluation could prove beneficial in the management of hip fracture older patients in order to prevent potential adverse outcomes.