Abstract: Buprenorphine (BPN) medication for opioid maintenance treatment in Finland consists predominantly of buprenorphine–naloxone (BNX). Both BPN and BNX are associated with diversion, abuse and non-medically supervised use worldwide. Our purpose was to estimate the proportion of BNX to all BPN-related fatalities. The material consisted of 225 deceased drug abusers in Finland from January 2010 to June 2011 with a positive BPN and/or norbuprenorphine (NOR) and/or naloxone (NX) finding in urine. The data were divided into three groups based on the urine NX and BPN concentrations. The “Parenteral BNX” group (>100μg/l NX) was presumed to consist of injecting or snorting BNX abusers and the “Parenteral BPN” group (>50μg/l BPN, 0μg/l NX) of injecting or snorting BPN abusers, whi…