This study explores how the way families treat professionals (interpersonal justice) and the trust professionals have in families relate to each other over time in organizations for persons with intellectual disabilities. Interpersonal justice is based on kindness, courtesy, respect, and dignity. Trust is an attitude reflecting the extent to which one party in a relationship believes the other to be trustworthy. We studied data from 179 professionals, measuring interpersonal justice and trust three times with a separation of four weeks. Our findings highlighted a double spiral model in which interpersonal justice and trust strengthen each other, acting as key drivers of dynamic processes. Specifically, interpersonal justice at one point in time (T1) was associated with trust at a later point (T2), which then was related to interpersonal justice again (T3). Similarly, trust at an earlier time (T1) was linked to interpersonal justice later (T2), which subsequently encouraged greater trust (T3).