This prospective, randomised double-blinded study was designed to assess the analgesic efficacy and occurrence of nausea when tramadol is added to a nonsteroidal anti-inflammatory drug to provide analgesia following day-case third molar teeth extraction. All patients received oral diclofenac pre-operatively and one of four treatments intra-operatively: fentanyl and metoclopramide, tramadol and metoclopramide, fentanyl and ondansetron, or tramadol and ondansetron. There were no significant differences between groups in scores for pain in the early postoperative period. However, there were significant differences in nausea scores at this time, with the fentanyl-ondansetron group having the lowest and the tramadol-ondansetron group having the highest scores. There were no significant differences in the incidence of pain or nausea in the following 24 h. We conclude that the addition of tramadol to diclofenac results in no useful improvement in analgesic effect, and that the use of ondansetron fails to reduce the nausea associated with tramadol.