The clinical diagnosis of mycosis of the feet (MF) requires laboratory confirmation. The structure of MF is dominated by dermatophytosis (DP), and among the causative agents of Trichophyton rubrum. The main method for diagnosing DP is bacterioscopic using alkali (KOH), the sensitivity of which reaches 83.9%. The purpose of the study is to improve the method of bacterioscopic diagnosis of DP and compare its effectiveness with the traditional method and the method of adhesive tape samples. Material and methods. 402 patients were examined in hospitals. Strands of true septic mycelium were found in 54.9%. The following methods were used: traditional (n=34), adhesive tape (n=44), alkaline preparation (AP) in a syringe (author’s method, n=51) and all three methods simultaneously per patient (n=92). For all patients with DP, an “Individual Registration Card” was filled out. Results. The AP material is put into a syringe to a volume of 5 ml. A special preparation is mixed: 30 g of KOH prep, 10 ml of glycerin and up to 100 ml of distilled water. It is drawn into the syringe until the AP material is completely immersed in liquid; then 1—3 drops are placed on a glass slide and viewed microscopically. The effectiveness of this method in the study of scrapings of the epidermis (91.1%) is 1.5 times higher than that of the traditional method (60.9%) and 1.3 times higher than the method of adhesive tape samples (68.5%). In the study of sections of affected nails, the AP method is 1.4 times more effective than the traditional method (70.8% and 50.7%, respectively). The effectiveness of the selected methods depended on the clinical form of DP. Using the AP method in the study of the epidermis allows you to increase the number of positive results within 3 days from 85.5% (1st day) to 100% (3rd day), and in the study of nails — from 32.6% (1st day) to 89.5% (2nd day) and 100% (3rd day). Conclusion. The AP method has a significant advantage compared to other methods.