Presentation of one patient with a highly infrequent association of transitional cells carcinoma and renal cells adenocarcinoma synchronically developed in the same renal unit. There has been very few cases diagnosed up to now, and only around 25 have been described in the literature. There is a clear predominance of males versus females, with haematuria being the most frequent sign present in 90% cases. Elective complementary examination is CT and the choice treatment can be either nephroureterectomy or extended nephrectomy based on early suspicion of transitional cells carcinoma or renal cells adenocarcinoma.