Routine followup of the groins of patients with penile squamous cell carcinoma after primary treatment consists of physical examination together with ultrasound of the groins, followed by fine needle aspiration cytology if suspicious. We assessed the value of this routine followup. Using ultrasound and fine needle aspiration cytology we assessed 247 patients during followup who were treated from 2004 to 2010 and underwent dynamic sentinel node biopsy only or observation of the inguinal regions. A negative result was defined as no evidence of metastatic disease after at least 2 years of followup. We calculated the sensitivity, specificity, and positive and negative predictive values of ultrasound and ultrasound guided fine needle aspiration cytology using standard statistical methods. Recurrence was diagnosed in 47 of 247 patients (55 groins). In 40 of 55 groins (73%) recurrence was detectable by physical examination. In 12 of 15 cases of nonpalpable recurrence (80%) ultrasound guided fine needle aspiration cytology revealed the recurrence. We considered 217 groins to be suspicious on ultrasound followed by fine needle aspiration cytology. Fine needle aspiration cytology revealed tumor in 49 groins and showed false-positive findings in 1 patient after negative completion lymphadenectomy. Sensitivity and specificity were 87.3% (48 of 55 cases) and 99.9% (1,304 of 1,305), respectively. Although inguinal recurrence manifests clinically in most patients, ultrasound guided fine needle aspiration cytology detected 80% of metastatic disease in patients with nonpalpable disease. Therefore, it has great value for detecting lymph node metastases during followup.