Mortality statistics published annually by the Registrar General Scotland for 1970-1989 are analysed. There has been a recent increase in the suicide rate amongst younger males in Scotland which cannot be explained by changes in the misattribution between suicides (ICD E950-E959) and undetermined deaths (ICD E980-E989). The increase is almost entirely attributable to hanging and the use of motor vehicle exhaust fumes. Analysis of the sex/age/method-specific suicide rates demonstrates that age-specific increases in the male suicide rate are linked to age-specific increases in the use of these two methods. The increased suicide rate involving motor vehicle exhaust fumes can be explained by changes in method availability and acceptability. The increased suicide rate involving hanging may be explained by increased acceptability, possibly flowing from the abolition of judicial hanging in 1965. The increased suicide rate in younger males may reflect a change in the proportion of suicidal attempts resulting in a completed suicide consequent on an age-specific shift to the use of more lethal methods, namely hanging and motor vehicle exhaust fumes. This possibility needs to be evaluated before assessing the influence of other social factors on the suicide rate.