OBJECTIVES: 1) To describe the trends of unintentional fatal poisonings by noxious substances in Kansas City, Missouri, from 1999 to 2008 and 2) to identify demographic risk factors associated with unintentional fatal poisonings. METHODS: This was a retrospective study using the death data for Kansas City, Missouri.  The data included the cause of death, sex, race, age, annual income, and Health Zone for each individual.  Unintentional fatal poisonings by noxious substances were identified by ICD-10 codes X40-X49.  Age-adjusted death rates and age-specific death rates of fatal poisonings were calculated for every year.  Chi-square tests were used to compare death rates for each demographic variable.  A multiple logistic regression analysis was conducted to measure the odds ratio (OR) of fatal poisonings due to sex, age, annual income, and Health Zone. RESULTS: Out of 38,785 deaths from all causes, 473 (1.2%) were identified to be due to unintentional fatal poisonings.  Age-adjusted death rates from unintentional fatal poisonings increased from 7 per 100,000 population in 1999 to 14 in 2008, while the all-cause age-adjusted death rates declined from 1999 to 2008.  From 1999 to 2003, the age group 35-44 years old had the highest death rate of unintentional fatal poisonings, whereas from year 2004 to 2008, the age group 45-54 years old had the highest death rate.  In the logistic regression, compared with the age group of 55 years and older, the age group of 35-44 years old had an OR of 44.06, and the age group of 45-54 years old had an OR of 21.49.  There were differences in ORs by sex, annual income, and Health Zone. CONCLUSIONS: Age-adjusted death rates of unintentional fatal poisonings increased for Kansas City, Missouri, from 1999 to 2008.  Sex, age, annual income, and Health Zone, were risk factors for unintentional fatal poisonings.