With the increasing number of cross-cultural nursing studies, many scholars have suggested methods for conducting cross-cultural research. However, rigor in cross-cultural research has rarely been addressed. In this paper, five evaluation criteria for rigor in cross-cultural nursing research are proposed based on a review of the literature related to cross-cultural research published from 1965 to 2003. The proposed evaluation criteria include: (a) cultural relevance; (b) contextuality; (c) appropriateness; (d) mutual respect; and (e) flexibility. We advocate that these evaluation criteria be used to ensure rigor of cross-cultural nursing research, whether quantitative or qualitative work.