WĂrtiĂů nephrectomy is preferable for the treatment of small renal tumors, because it spares the renal parenchima, avoiding a possible chronic nephropathy. During the ƉrĞŽƉĞrĂtiǀĞ ĞǀĂůƵĂtiŽn of these ƉĂtiĞnƚƐ͕ the nephrometry score is usually made. It is subject to mƵůtiƉůĞ bias, which could lead to incorrect diagnosis. In this ĂrticůĞ͕ we expose the technical ĚŝĸcƵůtiĞƐ during the use of the nephrometry score. This ƉƵbůŝcĂtiŽn has the purpose to enlighten the technical qƵĞƐtiŽnƐ regarding the rĞĂůŝnjĂtiŽn of necessary measures for the nephrometry score, as well as anatomical ǀĂrŝĂtiŽnƐ and ǀŝƐƵĂůŝnjĂtiŽn modes, focusing on technical care to be taken to avoid false ŝnĨŽrmĂtiŽn which might impair the ĮnĂů scoring and, thus, the report.