Olsson E, Ahl H, Bengtsson K, et al. - Although there are numerous studies investigating the burden of pain in newborn infants, limited information exists regarding the appropriateness of the use of pain scales according to the specific type of pain or infant condition. Researchers conducted this systematic review examining the reporting of neonatal pain scales in randomized trials. Performing a systematic search in Embase, PubMed, PsycINFO, CINAHL, Cochrane Library, Scopus, and Luxid, they identified 3,718 trials. Of these, 352 with 29,137 infants and 22 published pain scales were included. Procedural pain was focussed in most studies (92%); the most frequently employed pain scales were the Premature Infant Pain Profile or Premature Infant Pain Profile—Revised (48%), followed by the Neonatal Infant Pain Scale (23%). Pain scales employed in 55 studies (16%) lacked validation for the specific neonatal population or type of pain. Ninety percent of all trials used six validated pain scales, although not always in the appropriate population or type of pain. Selection of appropriate scales is recommended depending on the type of pain and population of infants included in a study. The ill suited use raises serious concerns regarding research ethics and use of resources.