In drug analysis, research involving the use of saliva sampling as non-invasive qualitative and quantitative techniques has become increasingly important. Saliva offers distinctive advantages over serum because it can be collected non-invasively by individuals with modest training, because of the growing interest in non-invasive procedures; this updated review evaluates the use of saliva in drug analysis and in therapeutic and toxicologic monitoring. So far, no device could be found to serve for all saliva analyses. Although highly sensitive methods of detection are required, most drugs can be detected in salivary secretions. Further studies will be required for proper relation between saliva and each drug. Also, saliva can be use a tool in toxicology.