The concentrations of morphine and codeine were investigated in hair from the head, axillary and pubic regions obtained from 12 fatal heroin cases. Hair preparation involves a decontamination procedure in dichloromethane at 37 degrees C for 15 min, solubilization in sodium hydroxyde at 100 degrees C for 5 min, neutralization with hydrochloric acid and centrifugation. After extraction in chloroform-isopropanol-n-heptane (50:17:33; v/v) at pH 9.2, drugs were derivatized with BSTFA + 1% TMCS and separated on a 12-m BP-5 capillary column. Quantification was done by GC/MS using selected ion monitoring. The highest morphine concentrations were found in pubic hair (0.80 to 41.34 ng/mg), followed by hair of the head (0.62 to 27.10 ng/mg), and axillary hair (0.40 to 24.20 ng/mg). Codeine was also detected in all samples, and the codeine-to-morphine ratios ranged from 0.069 to 0.273. The differences observed in drug concentration in the 3 types of hair are discussed in the light of the existing literature.