Objective: To determine whether differences exist for older persons presenting to Emergency Departments (EDs) with lower back pain (LBP) in terms of management, health service resource use and cost when compared to younger patients with LBP. Methods: Retrospective analysis of routinely collected electronic medical record data from January 2015 to July 2021. Data from 11,098 adults presenting with LBP to two large regional Australian EDs were analysed over a 5-year period. Rates of presentation, investigation, medication use, spinal surgery and cost were assessed for all participants with respect to age groups (over or under 65 years of age), diagnosis and time. Multivariable logistic regression analysis was employed to assess the contribution of presentation characteristics to the risk of inpatient admission and to investigate the variable effect of patient age. Results: Older people represented 23% (n = 2565) of all LBP presentations, with a growing proportion of presentations over time. More than 1 in 4 patients over 65 were admitted (n = 703, 27%), with CT imaging being proportionately three times more prevalent (24% vs. 6%), and average cost double (AU$3973 vs. $1671) that of the younger population. Consultation by an ED physiotherapist was associated with lower admission risk across all adult presentations (OR 0.52, 95% CI [0.40 to 0.67]). Conclusions: Older persons are over-represented amongst gradually increasing rates of LBP presentations to EDs and associated with escalating cost of care and hospital resource use. Older patients present a different clinical and economic profile to younger patients, supporting the provision of individualised management recommendations.