Delays between time of sampling and time of toxicological analysis are common, therefore the length of time that postmortem blood can be stored at various temperatures (e.g. 4°, 25°, –20° C) was evaluated for the effect on the stability of morphine and buprenorphine from day one up to one year. Solid phase extraction and GC-MS were used for the isolation and quantification of the drugs. Morphine and buprenorphine were found to be very stable for up to 6 months under these storage conditions, where at least 85% and 77% of morphine and buprenorphine respectively, were recovered. The study showed that a reasonable amount of the drugs (not less than 70%) was still detectable after one year of storage regardless of the temperature when blood samples were stored in silanized glass vessels.