AIMS:To describe and evaluate pain scales used to measure nipple pain in breastfeeding women and to identify nipple pain intensity in women with or without nipple damage. BACKGROUND:Nipple pain is one of the most common reasons given for premature cessation of breastfeeding. However, there are no agreed tools to measure pain and no previous reviews have provided summary estimates of pain scores. DESIGN:Systematic review. DATA SOURCES:Medline, CINAHL, Scopus, Web of Science, SciELO, and LILACS. REVIEW METHODS:We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The guiding question was: How is nipple pain in breastfeeding women measured and how severe is it? We analysed articles published up to February 2018, excluded review articles and those that did not present the level of nipple pain or tools to estimate pain severity. RESULTS:A total of 1,023 articles were identified and 25 were included in the review after applying the exclusion criteria. The Numeric Rating Scale (nine studies) and Visual Analogue Scale (seven studies) were the most prevalent tools for measuring pain. Using a pain score between 0-10, women with nipple damage reported a weighted mean of 6.2 in the first week and 5.8 after that period; women without damage reported a weighted mean of 2.7. CONCLUSION:Women with nipple damage consistently reported a higher level of pain than women without damage. To prevent premature cessation of breastfeeding, it is important to help new mothers avoid nipple damage.