Some scholars question whether procedural justice is the key driver in promoting support for the police across all cultural contexts. In this study we examine the relationship between procedural justice, police performance, trust in the police and the willingness to cooperate with the police, and we compare Vietnamese and Indian ancestral groups with the general population in Australia. We find that procedural justice is less effective in encouraging cooperation with the police among Vietnamese and Indian ancestral groups when compared with a general population group. Procedural justice is also found to be less effective in promoting trust among Vietnamese participants, compared with the general population group. Instead, police performance is found to be more effective in promoting trust in the police among Vietnamese participants. We set out to explain these observed differences and describe why some ethnic minority groups may judge process-based factors to be less important when it comes to trusting the police or being willing to cooperate with the police.