Objective: To examine the extent to which local health department (LHD) assurance of select services known to promote and protect the health of older adults is associated with more favorable population health indicators among seniors. Design: Data from the California Health Interview Survey (CHIS: 2003, 2005, and 2007) were linked with the 2005 wave of the National Association of County and City Health Officials profile survey and the Area Resource File to assess the association of LHD assurance and senior health indicators. Assurance was measured by an index of 5 services, either directly provided or contracted by LHDs: cancer screening, injury prevention, comprehensive primary care, home health care, and chronic disease prevention. Multilevel regression models estimated the association of LHD assurance of services and each of 6 older adult health indicators, controlling for individual, LHD, and county characteristics that included key social determinants of health, such as poverty. Setting: Fifty-seven California counties. Participants: 33,154 older adults (age 65 and older). Main Outcome Measures: Colorectal cancer screening, mammography, healthy eating, physical activity, and multiple falls among older adults. Results: Local health departments provided or contracted a median of 2 of the 5 services. In adjusted analyses, LHD assurance of services was generally unassociated with the seniors' health behaviors, screening, and falls. Greater LHD expenditures per capita were associated with significantly better mammography screening rates (adjusted odds ratio [AOR] = 1.22, P < 0.01) compared to jurisdictions in the bottom one-third of per capita LHD spending. Greater county-level poverty (a social determinant of health) was associated with greater junk food consumption (AOR = 1.14, P < 0.01) and worse fruit and vegetable consumption (AOR = 0.97, P < 0.01). Highly impoverished counties were consistently in the bottom quartile of performance across all indicators. Conclusions: The LHD's assurance of select services known to promote and protect the health of older adults does not appear to translate into higher rates of colorectal cancer screening, mammography, healthy eating, physical activity, and fewer falls among seniors. County-level poverty is most strongly associated with older adult health, underscoring a key barrier to address in local senior health improvement efforts.