An adequate analgesic strategy is important to improve the postoperative recovery and welfare of laboratory rats and mice. It is desirable that the method for administering the drug is non-invasive and stress-free. We have previously validated a method for administering buprenorphine in a nut paste for voluntary ingestion. This method has many advantages over parenteral administration. To use the method in a successful way, however, it is important to prepare and administer the mix correctly. The present paper describes in detail how to implement the method, by means of habituation, presentation, adequate concentrations and amounts of buprenorphine/nut paste, and dosage of buprenorphine to rats and mice.