Background: Affective and reciprocal interactions with others are essential for persons with profound intellectual and multiple disabilities (PIMD), but it is a challenge to assess their quality. This study aimed to investigate the usefulness of instruments from parent-infant research to evaluate these interactions. Method: Eighteen videotaped staff-client interactions were coded with the Emotional Availability Scales, the Maternal/Child Behavior Rating Scales, and the Revised Erickson Scales. Results: The scales could generally be applied to persons with PIMD and substantial interobserver agreement was found. The tools' subscales appeared to be distinct but there was also evidence that they measure an overarching construct. Client and staff interactive behaviours were highly related. Convergent validity was demonstrated by strong correlations between theoretically related dimensions. An acceptable range in scores, a ceiling-effect, and relative high mean scores occurred. Conclusions: The instruments' applicability and usefulness was demonstrated in this study, which offers directions for future research and intervention.