Twenty-eight cases from 2004-2007 involving olanzapine were nalyzed at the San Diego County Medical Examiner's Office lanzapine was initially detected by gas chromatography coupled ith mass spectrometry (GC-MS), and then confirmed by GC with itrogen-phosphorus detector. In cases where olanzapine was etected, concentrations in peripheral blood (PB), central blood CB), liver, and vitreous were determined if available. In the six lanzapine-only deaths, average olanzapine concentrations (mean ±eviation) were 3.2 ±(PB), 4.5 ± 2.6 mg/L CB), 40 ± 29 mg/kg (liver), and 1.6 ± 0.50 mg/L (vitreous). This as compared to the 10 non-olanzapine-related deaths, which showed average olanzapine concentrations of 0.26 ± 0.13 mg/L (PB), 0.29 ± 0.17 mg/L (CB), 5.6 ± 5.6 mg/kg (liver), and 0.24 ± 0.38 mg/L (vitreous). The remaining 10 multi-drug deaths had average concentrations of 0.59 ± 0.33 mg/L (PB), 0.64 ± 0.60 mg/L (CB), 5.9 ± 4.3 mg/kg (liver), and 0.78 ± 0.91 mg/L (vitreous). Concentrations of olanzapine associated with toxicity were found to be in the range of 1.4-6.2 mg/L (PB), 1.1-7.4 mg/L (CB), 14-88 mg/kg (liver), and 1.1-2.1 mg/L (vitreous) Concentrations associated with therapeutic use were found to be in the range of 0.11-0.43 mg/L (PB), 0-0.53 mg/L (CB), 0-8.6 mg/kg (liver), and 0-0.98 mg/L (vitreous). Deaths attributed solely to olanzapine were distinguished by a 10-fold or more increase in tissue concentrations over those found in the non-olanzapine-related deaths.