Background: About half of the pts operated for residual RP mass after chemo for NSGCT do not benefit from surgery because the residual mass contains only necrosis. We sought to assess the accuracy of “intuition” or experienced guess by urologists at a large tertiary referral center for identifying malignant tumors (teratoma and/or viable cancer cells) after primary chemo for disseminated NSGCT. Methods: We included pts with persistent RP mass after chemo who were referred to urology clinic for assessment for post chemo RP lymph node dissection (PC RPLND). All pts had normal tumor markers (serum HCG and AFP) after completion of chemo and at the time of analysis. The urologists looked at clinical data – pt history, orchiectomy histology, post chemo CT scans, tumor markers and made an intuitional analysis of the residual mass as teratoma, necrosis or malignancy. After pts had RPLND, their histology was compared to the intuition analyses. Results: Pt characteristics are summarized in Table 1. The urologists’ intuition matched the final pathology in 37/53 (70%) cases. Table 2 shows number of correct predictions. Table 3 shows the histology compared to predictions. There was a trend towards an interaction of residual mass size and urologist intuition to correctly predict histology, but this was not statistically significant (p = 0.57). Conclusions: Urologists at a tertiary care center with experience of treating NSGCT pts can predict histology reasonably well. Future directions will be implemented towards combining this with radiology and potential molecular assessments to reduce surgeries in pts with necrosis.