We examined the association between telomere length and prenatal tobacco exposure (PTE) in 104 children aged 4 to 14 years. Salivary telomere length (STL) was determined from salivary DNA using quantitative polymerase chain reaction. Of the children, 18% had maternal reported PTE. Mean STL was significantly lower among children with PTE (6.4 vs 7.5, P < .05). Findings extend the literature demonstrating the negative long-term effects of PTE to include a cellular marker of aging linked to multiple negative health outcomes.