ABSTRACT Objective The Perth Emotion Regulation Competency Inventory (PERCI) was developed to assess emotion regulation abilities for negative and positive emotions. This study aimed to develop a Japanese version of the PERCI and to examine its psychometric properties. Methods Before the following surveys, we developed a draft of the Japanese version, intending to translate the questions into easy-to-understand Japanese to avoid spoiling the original version’s meaning. We conducted a preliminary survey of 23 undergraduate students, and the results confirmed the face validity of the Japanese PERCI. Second, the first cross-sectional survey examined descriptive statistics, factor structure, internal consistency, and construct validity of the PERCI with Japanese adult participants (165 men and 179 women, mean = 52.07 years, SD = 13.51, age range = 19–83). We also conducted the follow-up survey (103 participants aged 25–83 years) to evaluate the test-retest reliability and construct validity. Results Confirmatory factor analysis indicated that the Japanese version had an eight-factor structure. Moreover, it demonstrated good internal consistency, acceptable test-retest reliability, and good evidence of construct validity. PERCI scores were not significantly correlated with expressive suppression, indicating that expressive suppression cannot be considered a maladaptive strategy in Japanese adults and is not directly associated with emotion dysregulation. Conclusions The Japanese PERCI can help assess the ability of Japanese adults to regulate positive and negative emotions. Our findings are expected to further clarify aspects of emotion dysregulation in the Japanese population and can be used as a tool for measuring the effectiveness of psychological interventions.