Background Recent studies have shown that it is possible to foster affective involvement between people with congenital deafblindness and their communication partners. Affective involvement is crucial for well‐being, and it is important to know whether it can also be fostered with people who have congenital deafblindness and intellectual disabilities. Methods This study used a multiple‐baseline design to examine whether an intervention based on the Intervention Model for Affective Involvement would (i) increase affective involvement between four participants with congenital deafblindness and intellectual disabilities and their 13 communication partners and (ii) increase the participants' positive emotions and decrease their negative emotions. Results In all cases, dyadic affective involvement increased, the participants' very positive emotions also increased and the participants' negative emotions decreased. Conclusion The results indicate that communication partners of persons with congenital deafblindness and intellectual disabilities can be successfully trained to foster affective involvement.