Key issues in cross-cultural assessment are discussed. The concepts of bias and equivalence are described as pivotal aspects in cross-cultural assessment.A taxonomy of bias and equivalence is described. It is argued that issues in cross-cultural assessment are relevant not just in cross-national studies but in any translation and adaptation of western instruments, even when these are not meant for cross-national comparison. The problems to be dealt with in the process of such translations and adaptations are described on the basis of four hypothetical studies.