The current investigation is a pathological study of the teaching– learning system in Tehran technical and vocational colleges. This is a descriptive study using survey as the data collection technique. The statistical population included 17437 students in the stated colleges, of which 376 students were selected as a sample using Cochran’ s formula and systematic random sampling method. Data collection involved employing the comprehensive teaching– learning system scale, designed based on five-point Likert scale. It included conceptual, structural, and functional dimensions to examine the comprehensive system of teaching– learning in the stated institutes. The conceptual dimension included “ subject and content of the teaching-learning, nature of teachinglearning, teaching– learning style and teaching– learning principles"; the structural dimension comprised “ strategic orientation, teaching-learning system design, and teaching– learning culture” , and the functional dimension encompassed “ the implementation of the teaching– learning process, leadership, management of teaching– learning process, and evaluation of teaching– learning effectiveness” . Having used Kolmogorov– Smirnov test to test the normality of the data, one sample t– test was employed to analyze the data using SPSS. The results demonstrated that such factors as teaching– learning style and teaching– learning principles (conceptual dimension), strategic orientation, teaching-learning system design, and teaching– learning culture (structural dimension), and the implementation of the teaching– learning process, leadership and management of teaching– learning process, and evaluation of teachinglearning effectiveness (functional dimension) are not in a desirable condition. The finding accentuates the presence of defects in the aforementioned dimensions. It was only in the conceptual dimension that the components of "subject and content of the teaching-learning, and nature of teaching-learning" were in an acceptable condition. This highlights the presence of deficiencies in the three conceptual, structural and functional dimensions of the teaching-learning system in Tehran technical and vocational colleges.