In order to investigate the reasons for a decrease in male suicide rates over the past few years in Portugal, suicide rates were compared with controversial cases & with homicide rates. The results show that, since 1980 & coinciding with the use of ICD-9, controversial cases have increased 12 & 21 times among males & females respectively. It is concluded by the authors that since 1980 there has been a significant underreporting of suicides in Portugal, which have been registered as controversial cases. (17 refs)