Awareness of the importance of cross-cultural aspects in psychological assessment appears to be increasing, with several comprehensive guidelines and position papers available. In practice, however, psychologists who work cross-culturally often face considerable difficulties and uncertainty, such as a general lack of adequate (and translated) instruments, validated adaptations, and norms appropriate for different types of patients. Here, the chapter authors analyze and discuss these issues for one particular field of psychological injury and law: symptom and performance validity assessment. Validity assessment aims at determining the credibility or trustworthiness of examinees’ symptom claims and their test profiles. Neither can be taken at face value in forensic contexts. Also, in clinical contexts, there is a growing body of literature questioning the long-held implicit view that psychological data should be accepted as valid without further inquiry. In cross-cultural contexts, validity assessment is often confronted with numerous additional challenges, adding to the restrictions posed to assessment in general. Taken in a worldwide context, the empirical database is poor, available instruments cover only a minor fraction of cultural and linguistic diversity, and cross-cultural validation of assessment instruments may be characterized as piecemeal rather than systematic.