Aims In this study we examine whether the recent, sharp increase in mortality in the United States due to accidental poisoning since 2000 is the result of the aging of the baby boom cohort or, instead, a historical trend apparent among decedents of all ages. Design We conducted an age?period?cohort analysis using data from the US Vital Statistics and the US Census covering the period 1968?2007. Setting and participants The United States population aged 15?64 years. Measurements Cause of death and demographic data as recorded on death certificates. Findings The increase in mortality due to accidental poisoning since the year 2000 stems primarily from a historical period effect across all ages for whites, but results in large part from a rate spike in the baby boom cohort among blacks. For all demographic groups baby boomers had higher odds of death due to accidental poisoning than the cohorts that came before and after them. Historical influences acting across all ages led to an increase in accidental poisoning mortality that was almost 10-fold for whites and threefold for blacks over the study period. Conclusions While the recent, sharp increase in accidental poisoning mortality stems in part from the aging of the baby boom cohort, substantially more of the increase results from influences unique to recent years that have affected all age groups. These results point to the need to bolster overdose prevention programs and policies as the historical increase in accidental poisoning mortality appears to continue unabated.