Eighty patients undergoing total hip arthroplasty (THA) were randomized to receive an ultrasound-guided transmuscular quadratus lumborum block (QLB) combined with local infiltrative analgesia (LIA) (n=40) or LIA alone (n=40). The primary outcome of interest was postoperative pain during the first active motion measured at 6 hours postoperatively. Other outcomes of interest included active and resting pain scores up to 72 hours postoperatively, intraoperative and postoperative opioid consumption, frequency of sleep interruption and time to first walk postoperatively. The QLB+LIA group had significantly lower pain scores at first active motion compared to the LIA group alone. The QLB+LIA group also had lower active and resting pain scores up to 24h postoperatively. Significantly lower amounts of intraoperative and postoperative opioids were consumed in the QLB+LIA group. The QLB+LIA group was able to walk sooner and reported significantly fewer disruptions in sleep on postoperative day zero. No differences in adverse events were found.