Abstract: Objective To investigate the clinical outcome of immediate inguinal lymph node dissection on the survival of the patients with penile carcinoma. Methods A total of 67 patients of penile carcinoma whose inguinal lymph nodes (ILN) were initial clinically impalpable, received inguinal lymph node dissection (ILND) from Dec 2008 to April 2014. Among them, 33 patients received immediate ILND within 1 month after the resection of penile cancer, while 34 patients underwent delayed ILND which was performed when ILN was found clinically apparent during follow-up. The Kaplan-Meier survival analysis was performed. The prognostic factors was evaluated by log-rank test , including age, morphology， location, T stage, grade of primary tumor, clinical status of ILN before ILND, lymphatic pathology, time to ILND. Cox proportional hazard model was used to find the independent risk factors on survival. Results The median age was 50 year-old (range 26 to 84 year-old). The median follow-up time was 23 months (range 3-76 months). The 3-year and 5-year overall survival were 70.1% and 65.4%, respectively, The 5-year survival rate in immediate ILND and delayed ILND group were 93.1%, and 33.7% respectively. Positive ILN metastasis was found in 7 patients from immediate ILND group but 26 patients from delayed ILND group.that the prognostic factors included T stage, tumor grade, clinical status of inguinal lymph nodes before ILND, and lymphatic pathology. Cox model found the status of inguinal lymph nodes was independent prognostic factor for the survival. Conclusion Inguinal lymph node metastasis is the important prognostic indicator of the survival of penile cancer. Immediate ILND could improve survival for the patients with clinically impalpable lymph nodes.