In order to gain an understanding of double duty caregiving (DDC), defined here as the provision of care to elderly relatives by practising health professionals, a DDC scale has been developed. This study tests the psychometric properties of the scale. Survey data were collected from a random sample of 187 female registered nurses who were employed and also provided care to elderly relatives. Nine factors contributing to DDC emerged from exploratory factor analysis. The DDC subscales were moderately correlated with the standardized health measures included in the study.The caregiving interface (degree of blurring between the professional and personal caregiving domains) was significantly negatively correlated with well-being and mental health.This result extends our understanding of the supports needed by those providing DDC.