To calculate the costs of suicide in Ireland. The paper identifies all episodes of suicide in Ireland in 2001 and 2002, and projects the economic costs arising from these episodes over subsequent years. All prices have been converted to 2001 Euros. Both direct and indirect costs were calculated. Indirect costs included both the cost of lost output and human costs. The total cost of suicide is estimated at over Euro 906 million in 2001, and over Euro 835 million in 2002 (in 2001 prices). This is equivalent to a little under 1% of the gross national product in Ireland for those years. The results show that investment in health education and health promotion can be justified on the basis of the costs associated with suicide in Ireland. These costs fall on individuals, families, and society. The huge human cost of suffering associated with suicide can also be prevented through appropriate intervention to prevent death occurring. It is important that any suicide prevention strategy should include an evaluative framework to ensure that investment occurs in the areas most likely to generate the highest returns in term of suicides prevented and lives saved.