Background <p>Prisoners are considered a vulnerable group in terms of health risks and limited access to health services. This study aimed to determine the health perceptions and health-promoting behaviors of Turkish prisoners, examine the relationship between these factors, and identify the predictors of health perceptions and health-promoting behaviors as a cross-sectional design.</p> Methods <p>This cross-sectional study was conducted between November 2023 and January 2024 with 234 prisoners convicted of criminal offenses in two open penal institutions in Eskişehir, Turkey. Data were collected using a sociodemographic information form, the Health Perception Scale, and the Healthy Lifestyle Behaviors Scale II. Statistical analyses included Independent Samples t-test, One-way ANOVA, Pearson correlation analysis, and multiple linear regression analysis to identify the predictors of health perceptions and health-promoting behaviors.</p> Results <p>The mean score of health perception among the prisoners was 51.43 ± 7.66, and the mean score of healthy lifestyle behaviors was 130.41 ± 26.90. A positive but weak correlation was found between health perception and healthy lifestyle behaviors (<i>r</i> = .319; <i>p</i> &lt; .001).</p> Conclusions <p>The findings highlight the importance of evaluating prisoners’ health perceptions and health-related behaviors. Prison nurses are recommended to routinely assess these factors and implement targeted interventions to support healthy lifestyle changes in prison populations.</p>