The present research examined people's (mis)interpretations of prosocial intergroup behaviors by investigating whether a helper's familiarity with the context influences the empathy and altruistic (vs. instrumental) motives recipients of help attribute to helpers. In four experiments we recruited participants from different cultural backgrounds (Kosovan Albanians and Swiss) and different age groups (adolescents and adults), and considered two different perspectives: participants either imagined themselves in a predicament (i.e., a mental stimulation) or learned about a fellow ingroup member in the same predicament (i.e., a real situation). In all experiments, we manipulated both helper categorization (ingroup vs. outgroup) and familiarity with the context (i.e., whether the situation happened in an ingroup vs. outgroup context). Results showed that participants attributed less empathy and less altruistic (vs. instrumental) motives to the helper and were less willing to accept help in the outgroup helper condition than in the ingroup helper condition. However, this pattern occurred mostly within ingroup contexts. Finally, perceptions of a helper's ability to provide a solution mediated the observed effects on the main dependent variables. We discuss the theoretical and practical implications of these findings for intergroup relations.