Background: Radical nephrectomy is the standard treatment of choice for localized renal cell carcinoma. Ensuring that patients' informational needs have been met before radical nephrectomy set the stage for successful management and improves recovery. Aims: Evaluate the effect of nursing teaching guideline on the level of anxiety before radical nephrectomy. Research design: True experimental research design (Pre-test and post-test). Setting: Assiut Urology and Nephrology Hospital. Patients: Sixty adult patients undergoing radical nephrectomy were distributed into two equal groups (study and control groups) 30 patients for each. Tools: (I) Patient assessment sheet, (II) State-Trait Anxiety Inventory for Adult, and (III) The designed nursing teaching guideline for patients undergoing radical nephrectomy. Results: Statistically significant differences were found between study and control groups regarding preoperative anxiety levels (P < 0.01). Conclusion: The levels of preoperative anxiety significantly reduce associated with preoperative nursing teaching guideline provision.