Data from 30 fatal cases of dextropropoxphene poisoning occurring in Northern Ireland over three years have been studied. All the victims had ingested more than therapeutic amounts, and many had also taken alcohol or other drugs. Most of the deaths were probably suicides. Death occurred very rapidly suggesting that the narcotic effects of dextropropoxyphene predominated, and this may explain the scarcity of clinical reports, It is suggested that many doctors are unaware of the danger of dextropropoxyphene in overdosage and that the problem of dextropropoxyphene poisoning in the United Kingdom has not been fully appreciated. This supposition, if correct, highlights the absence of a satisfactory early-warning system for serious drug effects including death.