Parent’s awareness that their child’s development is not proceeding as they expected can create an unanticipated transition from being a parent to becoming the parent of a child with a developmental diagnosis. While many transition theories contribute to our understanding of how parents’ experience change over time, many traditional transition models are not family-centered and do not provide a strengths-based perspective of parents’ experiences during this transition. This paper describes the process of theory derivation to develop a strengths-based theory of parental transformation (STPT). We used the theory of well-being of refugee women experiencing cultural transition to gain insights into parents’ experiences related to their child’s diagnosis. We propose that the STPT addresses a gap in the literature by situating the diagnostic process within a strengths’ based framework that aligns with contemporary perspectives regarding disability. The STPT emphasizes understanding parents’ experiences and needs in ways that promote personal growth to support the parent and child.