Suicide represents a serious public health problem throughout the world. Toxicology plays a crucial role in the investigation of suicide. Psychoactive substances are recognized in the literature as the main suicide-generating stimuli. Ethanol is known to produce disinhibition and increased self-confidence. Other psychoactive substances can predominantly be central nervous system (CNS) stimulants or depressors. In cases of overdose as a method of suicide, the link between toxicology and the method of suicide is a matter of common sense and requires no additional explanation. On the other hand, in cases of non-overdose suicides this link is much more complex, and has not yet been extensively elucidated. We hypothesize a close relationship between toxicology and the choice of the method of committing suicide other than overdose. Negative findings may reflect either poor prescribed drug compliance in psychiatric patients, or suggest the role of other (non-toxicological) suicide-generating stimuli. On the other hand, positive findings influence the choice of the suicide method in a way that it depends on the prevalence of either stimulation or depression of the CNS, and consequent degree of behavioral aggression. Simplified, if the prevailing effect is CNS stimulation (with an increase in aggression), the method would be more drastic and more immediately fatal one, while with the CNS depression the method would be less immediately fatal and less drastic. There are only a few studies on the prevalence of psychoactive substances amongst completed suicides and even fewer studies have attempted to examine the relationship between substances used and the circumstances surrounding suicide. In evaluation of our hypothesis, we suggest thorough studies of toxicology and the choice of methods of committing suicides other than overdose. The scientific knowledge gained this way will eventually make toxicology a useful target in suicide prevention, especially amongst younger population.