The aim of this research is to determine school principals' opinions on the in-class inspections carried out by inspectors of the Ministry of National Education of Turkey (MEB). The study was modeled as a convergent parallel design, one of the mixed methods which combined qualitative and quantitative methods. For data collection, the researchers developed and used a structured data collection form consisting of open- and closed-ended questions. The purposeful sampling method of convenience sampling was employed in the study, and the study group consisted of 132 school principals. The qualitative data obtained were subjected to descriptive analysis and analytic generalization, whereas frequency and percentage statistics were used to analyze the quantitative data. The research was found that, although school principals believe in the necessity of an inspection system, they generally have negative opinions of the process of the inspections conducted by MEB inspectors. In other words, their negative opinions concern the structure and functioning of the inspection system rather than its existence. Hence, we conclude that the education inspection system in Turkey needs to be improved so that it conforms to contemporary theories and practices.