Introduction: Left radical nephrectomy is the second most common cause of incidental splenectomy during transabdominal oncological surgery in the upper left quadrant of the abdomen. The potential sequelae of splenic ablation are often underestimated and generally no systematic planned efforts have been undertaken to avoid a splenic injury. Material and Methods: We evaluated the incidence of iatrogenic splenectomy in 333 cases of left radical nephrectomy for renal cancer performed at our institute between 1970 and 1999. Two slightly different surgical techniques were adopted and after 1995 particular attention was paid to the possible causes of intraoperative splenic injury and how to avoid it. In the first group of patients (1970–1994) an anterolateral xipho-umbilical-subcostal approach was used, and in the second group (1995–1999) a cruciate ‘Mercedes-like’ incision was always adopted. Results: The incidence of iatrogenic splenectomy in the first group of patients was 13.2%, and only 2.6% in the second group. The mortality rate in the first group of patients was 6%; no mortality has been recorded in the second group. Postoperative infections averaged 12.1% in the first group and 11.6% in the second, without any difference between the two groups. However, if we consider the incidence of postoperative infections in splenectomy cases, the incidence reaches 24.2% in the first group versus no cases in the second. Conclusions: Incidental splenectomy is a potentially severe complication of transabdominal left radical nephrectomy and is often considered a price that has to be paid, particularly in cases of large tumoral masses. A more detailed knowledge of splenic anatomy, a critical consideration of the intraoperative factors that may lead to splenectomy, and the adoption of a surgical tactic borrowed from the techniques of liver transplant significantly lower the incidence of iatrogenic splenectomy.