Objectives: Eco-anxiety, a novel conceptualization of anxiety in relation to ecological problems, has become a significant subject of interest in psychology. The Hogg Eco-Anxiety Scale (HEAS-13) is a recently developed, valid, and reliable measure of eco-anxiety. The present study aimed to investigate the psychometric properties of the HEAS-13 in Turkish-speaking samples. Methods: 605 individuals, recruited via social media and the internet, participated in the study. The sample was randomly split in half (first sample, 69.00% and second sample, 70.90% females), and exploratory and confirmatory factor analyses were conducted on separate samples. The concurrent and incremental validities were evaluated in the total sample. The three-week test-retest reliability of the HEAS-13 was assessed in a third separate sample (83.13% females). Results: Exploratory and confirmatory factor analyses found and validated a four-factor structure with 13 items. The associations of HEAS-13 with concurrent measures indicated that the scale had good concurrent validity. The anxiety and behavioral symptoms subscales of the HEAS-13 explained the additional variance (6.60%) in pro-environmental behavior beyond activist identity and commitment. Finally, the HEAS-13 and its subscales had good internal consistency coefficients, ranging from 0.82 to 0.93. and mediocre three-week intra-class correlations, ranging from 0.47 to 0.56. Conclusion: The Turkish HEAS-13 was a valid and reliable measure of eco-anxiety that can be used to assess anxiety about ecological problems. Moreover, optimizing levels of anxiety symptoms, alleviating behavioral symptoms, and enhancing individuals' activist identity and commitment may be targets for interventions aiming to increase pro-environmental behaviors.