Aims: Career maturity and career self-efficacy, as two important parameters for choosing a career path, play a key role in promoting general health by influencing individual health. This study was conducted with the aim of examining the effectiveness of training World Health Organization model of healthy lifestyle on career maturity and career self- efficacy in juvenile offenders.

Materials & Methods: The current study followed a pre-test-post-test design with a control group and was carried out on all juvenile offenders of Chatra center in Tehran in 2018. A sample consisting of 20 juvenile offenders, who obtained low scores on Career Maturity and Career Self-Efficacy questionnaire, were randomly selected and assigned into two groups, a control and experimental group (10 people in each one). Ten 90-minutes sessions of healthy lifestyle training were carried out on the experimental group. After finishing the sessions, a post-test was conducted on both experimental and control groups. Data were analyzed by Multivariable Analyze of Covariance using SPSS24.

Findings: The mean scores of career maturity and career self- efficacy obtained by experimental group in the post-test, had a significant increase compared to the control group.

Conclusion: The World Health Organization model of healthy lifestyle training promotes career maturity and career self- efficacy in juvenile offenders.