The paper reviews the main problems and achievements in using a diagnostic technique, such as fluorescence diagnosis (FD), for non-muscle-invasive bladder cancer (NMIBC). The statistics on BC prevalence in the structure of cancer incidence in Russia and the world provide a rationale for the urgency of recognition of the early forms of urothelial cancer. The paper characterizes cystoscopy, a standard procedure to examine the bladder, the possibilities and limitations of an endoscopic approach in the white light (WL) imaging of pathological changes in the bladder mucosa. Taking into account the recurrence rate of NMIBC during the first year after surgical treatment (transurethral resection), the authors emphasize the need to search for new methods to diagnose tumor foci at an early stage, which became possible due to FD using different photosensitizers. The paper defines FD known as WL fluorescence cystoscopy (FCS); the necessary introduction of FCS in practical health care is beyond question and this technique is widely used to diagnose malignant tumors, including in urologic oncology. The physicochemical characteristics of fluorochromes (fotoditazin, alasens, hexasens) used to detect transitional-cell BC and the advantages of the method over WL cystoscopy are described. The mechanism of endogenous photoactive protoporphyrin IX synthesis in tumor cells is reflected, which determines the fluorescent contrast between malignant and intact tissues. Thus, the data available in the literature on the early diagnosis of NMIBC necessitate the search for novel photosensitizers having higher photosensitizing activity, tumorigenesis, and excitatory effects, as well as the development of highly sensitive and reliable diagnostic equipment.