Heroin manufacturing and distribution by criminal and terrorist organizations produce illicit economic benefits from the opium and heroin trade and result in devastating societal problems. Heroin chemical signatures provide important information to law enforcement and the intelligence community in order to combat the national and international heroin epidemic. Authentic (known origin) heroin samples from Southeast Asia (SEA), Southwest Asia (SWA), South America (SA) and SA-like heroin manufactured in Mexico (MEX-SA), were prepared for chemical analysis by microwave-assisted acid digestion. Strontium concentration data were acquired using inductively-coupled plasma mass spectrometry (ICP-MS). The samples having sufficient [88Sr] (1.25µg/g in the solid sample) were purified by ion exchange resin and strontium isotope ratio (87Sr/86Sr) values were measured using multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS).South American and MEX-SA heroin samples are presently the most challenging regions to differentiate by analysis of their organic compositions. The SA and MEX-SA heroin samples were correctly classified 82% and 77% of the time, respectively, when the 87Sr/86Sr values of individual authentic samples were compared to the overall mean values from the four regions. This is the first reporting on the use of 87Sr/86Sr analysis of heroin for the profiling of samples from specific geographic regions. In addition, a value of 87Sr/86Sr for the National Institute of Standards and Testing’s standard reference material NIST SRM 1570a (spinach leaves) of 0.70905±0.00002 (95% confidence interval, n=3) is also reported for the first time.