The presence of cocaine was confirmed in the saliva of two male human subjects who had received intravenous doses of cocaine. For one subject, the saliva:plasma concentration ratios varied from 2.96 to 0.5 over time following drug administration. Correlations of saliva to plasma cocaine levels were highly significant (p < 0.001) across doses of 15, 20, and 40 mg of intravenously administered cocaine. These findings are important in that they allow monitoring blood levels of cocaine after intravenous infusion in a non-invasive manner, and could form the basis for development of a non-invasive screen for active cocaine levels in saliva.