This study evaluated the effects of using a heating pad during cystoscopy on anxiety, pain, and distress in female patients. Seventy-four female patients who underwent rigid cystoscopy between January 2017 and August 2017 were randomized to either the experimental group using a heating pad (n = 37) or the control group using a pad without heat (n = 37). In the experimental group, a heating pad was applied to the patient's sacrum during cystoscopy. All patients completed the State-Trait Anxiety Inventory-S (STAI-S, 20-80) before and after the procedure and assessed their degree of pain and distress after the procedure using a visual analog scale (0-10). Systolic and diastolic blood pressure and pulse rate were also measured before and after the procedure. Demographic characteristics, mean age, procedure duration, and pre- and post-procedural systolic and diastolic blood pressures and pulse rate were statistically similar between the experimental and control groups. The mean STAI-S score of the experimental group was significantly lower than that in the control group (33.1 ± 10.1 vs 48.2 ± 11.1, p < 0.001). The experimental group had significantly lower pain and distress scores (visual analog scale, 3.8 ± 1.6 and 3.8 ± 1.8 respectively,) than the control group (6.4 ± 1.9 and 6.3 ± 2.1 respectively, both p < 0.001). Using a heating pad during cystoscopy significantly reduced female patients' anxiety, pain, and distress. We found this to be a safe, simple, and effective tool to use during cystoscopy.