Background: Persistent or increased long-term opioid consumption has previously been described following total hip- (THA) and knee arthroplasty (TKA). However, detailed information on postoperative analgesic consumption trajectories and risk factors associated with continued need of analgesics in fast-track THA and TKA is sparse. Methods: This is a descriptive multicentre study in primary unilateral fast-track THA or TKA with prospective data on patient characteristics and information on reimbursement entitled dispensed prescriptions of paracetamol, non-steroidal anti-inflammatory drugs, opioids, anticonvulsants and antidepressants 1 month preoperatively and 1 year postoperatively. Patients were stratified according to preoperative opioid use. Postoperative analgesic consumption trajectories were stratified as increased, decreased or no use compared to the preoperative period. Results: Of 8975 patients (4849 THA/4126 TKA), 33.9% had relevant reimbursed prescriptions 9–12 months postoperatively. Of 2136 (23.8%) patients with preoperative opioid use, 3.4% had unchanged opioid consumption at 9–12 months postoperatively. However, increased opioid consumption after 9–12 months occurred in 17.6 (TKA) and 10.2% (THA) compared to 9.9 and 6.3% in opioid-naive TKA and THA patients, respectively. Increased NSAID and paracetamol use was seen in 11.5 and 12.4% of all patients. Preoperative analgesic use (any), TKA, psychiatric disorder, tobacco abuse, cardiac disease and use of walking aids were associated with increased opioid consumption. Conclusion: Continued and increased opioid and other analgesic use occur in a clinically significant proportion of fast-track TKA and THA patients 9–12 months postoperatively, suggesting treatment failure and need for early intervention. Preoperative risk assessment may allow identification of patients in risk of increased postoperative opioid consumption. Significance: We found a considerable fraction of patients with continued or increased opioid consumption 9–12 months after fast-track THA and TKA. Increase in opioid consumption was more frequent in preoperative opioid users than opioid-naive patients, but a pattern of increased analgesic consumption was present across all analgesics. Our data demonstrate a need for increased focus on long-term analgesic strategies and postoperative follow-up after THA and TKA, especially in preoperative opioid users.