The aim of this study was to determine the effects of the 4-7-8 breathing technique on sleep quality, pain, and recovery quality in patients undergoing transurethral resection of the bladder (TUR-B). The population of the study will consist of patients who undergo TUR-B in the urology clinics of Tarsus State Hospital. In determining the sample size, the number of samples calculated based on the pain variable in reference studies was minimal; therefore, an effect size of 0.80, considered the upper limit, was taken as the basis. Using a power level of 90% and a two-tailed significance level (1-α), the calculation performed with G\*Power (version 3.1) resulted in a minimum total sample size of 68 patients, with 34 patients in each group (study group = 34; control group = 34). Data in the study will be collected using the "Descriptive Characteristics Form," "Richard Campbell Sleep Questionnaire," "Quality of Recovery-15 Scale," and "Visual Analog Scale." When the researchers visit the patient, they will first provide the "Informed Consent Form" and then have the patient complete the "Descriptive Characteristics Form," "Richard Campbell Sleep Questionnaire," and "Quality of Recovery-15 Scale." The researcher will then learn from another researcher (MB), who will not be involved in data collection, which group the patient belongs to. Patients in the study group will be taught the 4-7-8 breathing technique by the researchers after their admission to the clinic. The patients will begin the application preoperatively and continue after returning to the clinic following the TUR-B procedure, starting from the 2nd hour after the effects of anesthesia have worn off. Initially, patients will be asked to perform the 4-7-8 breathing technique under the guidance of the researchers, and then continue the practice under researcher supervision. Subsequently, until discharge, patients will perform sets of four breaths every two hours. The control group will receive the routine postoperative procedures and care in the clinic. All patients will be assessed with the "Richard Campbell Sleep Questionnaire" and "Quality of Recovery-15 Scale" at the 24th hour postoperatively, and with the "Visual Analog Scale" at the 4th, 8th, 12th, and 24th postoperative hours.