INTRODUCTION: Completeness of Global Burden of Disease (GBD) Study data is acknowledged as a limitation. To date, no study has evaluated this issue for low back pain, a leading contributor to disease burden globally. METHODS: We retrieved reports, in any language, based on citation details from the GBD 2017 study website. Pairs of raters independently extracted the following data: number of prevalence reports tallied across countries, age groups, gender and years from 1987 to 2017. We also considered if studies enrolled a representative sample and/or used an acceptable measure of low back pain. RESULTS: We retrieved 488 country-level reports that provide prevalence data for 103 of 204 countries (50.5%), with most prevalence reports (61%) being for high-income countries. Only 16 countries (7.8%) have prevalence reports for each of the three decades of the GBD. Most of the reports (79%) did not use an acceptable measure of low back pain when estimating prevalence. CONCLUSION: We found incomplete coverage across countries and time, and limitations in the primary prevalence studies included in the GBD 2017 study. This means there is considerable uncertainty about GBD estimates of low back pain prevalence and the disease burden metrics derived from prevalence.