Courtesy stigma refers to the stigmatization an unaffected person experiences due to his or her relationship with a person who bears a stigma. Parents of children with genetic conditions are particularly vulnerable to courtesy stigma, but little research has been done to explore this phenomenon. The purpose of this study was to investigate the courtesy stigma experiences of parents of children with Proteus syndrome (PS) and related overgrowth conditions. Thematic analysis of transcripts from 31 parents identified three distinct themes: stigma experiences, social-emotional reactions to stigmatizing encounters, and coping responses. Four types of stigmatizing experiences were identified: intrusive inquires, staring and pointing, devaluing remarks, and social withdrawal. Additionally, we uncovered eight strategies parents used to cope with courtesy stigma: attributing cause, assigning meaning to social exchanges, concealing, withdrawing socially, taking the offensive, employing indifference, instructing and learning from family, and educating others. Parents' choices of strategy type were found to be context dependent and evolved over time. This is the first study to document the adaptive evolution of coping strategies to offset courtesy stigma by parents of children with genetic conditions. These results provide groundwork for genetic counseling interventions aimed at addressing issues of courtesy stigma and further investigation of the phenomenon itself.