Restriction of means for suicide is an important part of suicide preventive strategies in different countries. The effect on method-specific suicide rate and overall suicide rate of restrictions on availability of carbon monoxide, barbiturates, and dextropropoxyphene was examined. From 1970 to 2000, overall suicide mortality and method-specific suicide mortality in Denmark were compared with official information about availability of barbiturates and analgesics and carbon monoxide in vehicle exhaust and household gas. Restrictions on availability of household gas with carbon monoxide content and barbiturates was associated with a decline in the number of suicides and suicides by self-poisoning with these compounds after controlling for the effect of calender year. Restricted access occurred concomittantly with a 55 percent decrease in suicide rate.