Aim. The objective of the present study was the optimization of the strategy for the treatment of the patients presenting with squamous epithelial neoplasms in the colon by improving the quality of their corrective diagnostics. Materials and methods. The study was designed to evaluate and compare the results of endoscopic and morphological diagnostics of 152 flat, flattened, and flat-penetrating squamous epithelial neoplasms of the colon detected in 86 patients (42 women and 44 men at the age from 39 to 79 years). The videoendoscopic diagnostics was carried out by means of colonoscopy in the combination with chromoscopy in the narrow-spectrum white light and with the use of the image magnification function. The analysis of neoplasm images and the evaluation of their character was based on the NICE, S. Kudo, T. Kimura, and Y. Sano classifications. Results. The diagnostic accuracy of the method employed during the routine examination in visible light for the detection of hyperplastic polyps was 70%, sessile serrated adenomas 95%, benign adenomas 92%, and malignized adenomas 100%. The application of the clarifying technologies has demonstrated their comparable diagnostic accuracy. Specifically, the hyperplastic polyps were correctly diagnosed in 72%, serrated adenomas in 94%, and malignized adenomas in 100% of the cases. Conclusion. Routine endoscopy (examination in white light) performed by the adequately trained operator having the necessary practical skills provides a powerful tool for the diagnostics of flat, flattened, and flat-penetrating squamous epithelial neoplasms of the colon that is practically similar to the modern technologies of corrective endoscopic diagnostics in terms of accuracy. The diagnostic conclusions based exclusively on the visual endoscopic picture suggesting the plausible morphological structure of the revealed squamous epithelial neoplasms of the colon are virtually as reliable as those obtained by means of their morphological identification.