Nai-Huan Hsiung,1 Yen Yang,1 Ming Shinn Lee,2 Koustuv Dalal,3 Graeme D Smith4 1Department of Nursing, College of Nursing, Tzu Chi University of Science and Technology, 2Department of Curriculum Design and Human Potentials Development, National Dong Hwa University, Hualien, Taiwan, Republic of China; 3Department of Public Health Science, School of Health Sciences, Örebro University, Örebro, Sweden; 4School of Nursing, Midwifery & Social Care, Edinburgh Napier University, Edinburgh, UK Abstract: This study describes the cultural adaptation and testing of the behavioral pain scale (BPS) and the critical-care pain observation tools (CPOT) for pain assessment in Taiwan. The cross-cultural adaptation followed the steps of translation, including forward translation, back-translation, evaluation of the translations by a committee of experts, adjustments, and then piloting of the prefinal versions of the BPS and the CPOT. A content validity index was used to assess content validities of the BPS and the CPOT, with 0.80 preset as the level that would be regarded as acceptable. The principal investigator then made adjustments when the content validity index was