Objectives: Since laboratory tests are an important component of health expenditures, it is important to understand the factors that cause unnecessary test use and take the necessary precautions in order to control health expenditures. The aim of this study is to determine physicians' views on factors affecting unnecessary laboratory test orders. Methods: A survey method was used to examine unnecessary laboratory test use from the physician's perspective. The construct validity of the survey, which consists of 28 items, was tested with exploratory factor analysis and a 5-factor structure was reached. The reliability of the survey was tested with the internal consistency coefficient and the Cronbach's alpha coefficient was found to be 0.85. Multivariate regression analysis was used to determine whether physicians' level of agreement with the possible reasons for unnecessary test use differed according to their personal characteristics. Results: Among the possible reasons for unnecessary test use, the dimension in which the physicians who responded to the survey agreed most was "Risk avoidance and patient demands,"and the dimension they agreed least on was "Excessively skeptical and detailed thinking."Regression analyzes determined that physicians' opinions about unnecessary test use varied significantly according to the demographic characteristics of physicians. Conclusions: The findings obtained as a result of the study are thought to be important for decision makers to understand the factors that cause unnecessary laboratory test use and to take the necessary managerial measures.