<p>Homes are private settings where smoking regulations are limited, increasing the vulnerability of young children to secondhand smoke exposure. This study aimed to assess the frequency and risk of secondhand smoke exposure among children under five at home. A cross-sectional study was conducted in 26 neighborhoods of the Kepez district in Antalya, Turkey, between September and November 2020, using multistage cluster sampling, and included 543 parents of children under five from the general population. Data were collected using a secondhand smoke exposure risk assessment algorithm, an attitude and knowledge form on secondhand smoke exposure, and a child health history form. Chi-square tests, t-tests, and multivariable logistic regression analyses were performed. Overall, 63.5% of children were at risk of secondhand smoke exposure at home. Children from households where expenses exceeded income had an 88% higher likelihood of exposure (OR = 1.88, 95% CI [1.23–2.85]). Parental preventive attitudes reduced exposure risk by 24% (OR = 0.76, 95% CI [0.61–0.96]), and higher parental knowledge reduced exposure risk by 34% (OR = 0.66, 95% CI [0.53–0.83]). Parental education level was not significantly associated with exposure. Financial hardship increases children’s exposure to secondhand smoke at home, whereas parental knowledge and preventive attitudes provide protection. These findings highlight the need for interventions targeting low-income families and strengthening parental awareness to reduce secondhand smoke exposure among young children.</p>