Posttraumatic growth reflects beneficial psychological processes in persons with traumatic experiences. Existing measures of growth were criticized due to their retrospective self-report format that may cause biases in capturing the growth processes in individuals with several specific kinds of trauma, such as physical or psychological disabilities of close family members, bereavement and some others kinds of traumatic experience. In this case, the feelings of guilt may prevent the persons from being aware of the favorable personal changes. The objective of this study was to develop and to evaluate an alternative measuring instrument that uses a status quo response format instead of retrospective items and covers additional areas of growth-related changes. The samples comprised 440 adult persons with traumatic experience, including 181 parents of children with mental and/or physical disabilities. Exploratory and confirmatory factor analyses revealed a 7-factors solution, corresponding to the following subscales: Relationships to Others, New Possibilities, Personal Strength, Appreciation of Life, Spiritual Changes, Generativity, and Openness. Results showed good reliability and concurrent validity. The PGSI is recommended particularly for use in longitudinal studies as well as in samples of persons whose trauma relates to a severe psychological or physical disability in their families.