Introduction: Low back pain has become a serious health problem due to its high frequency and social, labor and economic impact. 90% of them correspond to non-specific low back pain, and in them routine examinations have proved to be non-cost-effective. Objective: To identify the frequency of the use of non-cost-effective tests in patients with a diagnosis of non-specific low back pain treated at The Almanzor Aguinaga Asenjo National Hospital, in 2014-2015. Material and methods: Cross-sectional descriptive study in patients aged 18 to 49 years with a diagnosis of non-specific low back pain (ICD-10 M54.5) attended by an outpatient clinic at The Almanzor Aguinaga Asenjo National Hospital in 2014-2015. Census sampling was used, including a clinical history of patients without a serious or specific underlying condition or who did not show any signs of alarm to suspect them. Excluded psychiatric comorbidities or fibromyalgia, obtaining 177 patients. A collection form validated by experts was used. The data was analyzed with SPSS v.22. Results: A frequency of non-cost-effective exams of 53,11% was found. The occupations with the highest physical load (60,64%) and the clinical services (47,87%) were the most frequent. The radiodiagnosis exams represent approximately 75% of the exams requested. A total unnecessary expense of s /.32125,21 equivalent to USD 9818.32 was obtained. Conclusions: There is a high frequency of the use of non-cost-effective tests in patients with non-specific low back pain, with radiodiagnosis being the most prescribed.