Aim. The research was carried out to determine the relationship between healthy lifestyle beliefs and hygiene behaviors of adolescents during the COVID 19 pandemic process. Materials and Methods. This descriptive-correlational research was carried out with 418 Turkish adolescents at the age of 13 to 18 years between March and August 2021. The data were collected online with a data collection tool, including a question form, the Healthy Lifestyle Belief Scale for Adolescents (HLBSA), and the Hygiene Behavior Scale (HBS). Percentage, mean, independent sample t-test, Mann-Whitney U-test, Kruskal-Wallis H test, Pearson correlation, and multiple regression analyses were used to analyze the data. Results. In the study, the variables of socioeconomic status, health perception, and knowledge of healthy living have shown a significant influence on the total HLBSA score; the variables of gender, maternal occupation, health perception and knowledge of healthy living have shown a significant impact on the total HBS score (p < 0.05). The total mean score of the HLBSA was 52.97 +/- 19.71, and the total mean score of the HBS was 102.07 +/- 23.02. There was a statistically significant relationship between the total HLBSA score and the total HBS score during the COVID-19 epidemic (p < 0.05). Conclusions. The study found that hygiene behaviors of adolescents during the pandemic process were good if their healthy lifestyle beliefs were good.