Background Treatment of acute pain in older patients is a common challenge faced in emergency departments (EDs). Despite many studies that have investigated chronic analgesic use in the elderly, data on patterns of acute use, especially in EDs, of analgesics according to patient characteristics is scarce. Objective To investigate sex- and age-related patterns of analgesic use in the Spanish EDs and determine differences in age-related patterns according to patient sex. Design A secondary analysis of the Emergency Department and Elderly Needs (EDEN) multipurpose cohort. Setting Fifty-two Spanish EDs (17% of Spanish EDs covering 25% of Spanish population) Participants All patients’ ≥65 years attending ED during 1 week (April 1–7, 2019). Patient characteristics recorded included age, sex, chronic treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and opiates, comorbidity, dependence, dementia, depression, ability to walk and previous falls. Analgesics used in the ED were categorized in three groups: non-NSAID non-opioids (mainly paracetamol and metamizole, PM), NSAIDs, and opiates. Outcome measures Frequency of analgesic use was quantified, and the relationship between sex and age and analgesic use (in general and for each analgesic group) was assessed by unadjusted and adjusted logistic regression and restricted cubic spline models. Interaction between sex and age was explored. Main results We included 24 573 patients, and 6678 (27.2%) received analgesics in the ED: 5551 (22.6%) PM, 1661 (6.8%) NSAIDs and 937 (3.8%) opiates (1312 received combinations). Analgesics were more frequently used in women (adjusted OR = 1.076, 95%CI = 1.014–1.142), as well as with NSAID (1.205, 1.083–1.341). Analgesic use increased with age, increasing PM and decreasing NSAIDs use. Opiate use remained quite constant across age and sex. Interaction of sex with age was present for the use of analgesics in general (P = 0.006), for PM (P < 0.001) and for opiates (P = 0.033), with higher use of all these analgesics in women. Conclusion Use of analgesics in older individuals in EDs is mildly augmented in women and increases with age, with PM use increasing and NSAIDs decreasing with age. Conversely, opiate use is quite constant according to sex and age. Age-related patterns differ according to sex, with age-related curves of women showing higher probabilities than those of men to receive any analgesic, PM or opiates.