Most of kidney transplanting surgeons tend to perform a left sided nephrectomy for donation and as demonstrated by anatomists, one of veins joints to left renal vein is left testicular vein which its flow may be damaged by manipulation of left renal vein during left nephrectomy. We aimed to evaluate changes of left side pampiniform veins plexus and testis following left side nephrectomy in kidney donors. During present cross-sectional study (Sep 2007-July 2008), 54 healthy males who candidate for left kidney donation underwent ultrasound study of left side pampiniform veins plexus diameter and left testis size before and 4 months after nephrectomy. Mean age of patients was 25.07 ± 2.49 years. The mean diameter of left pampiniform vein diameter before and 4 months after nephrecomy were 1.37 ± 0.40 and 2.04 ± 0.49 mm, respectively, and the mean size of left testis before and 3 months after nephrecomy were 21.86 ± 2.47 and 21.50 ± 2.17 cc, respectively. The mean of left pampiniform vein diameter was significantly increased 3 months after nephrectomy (P<0.001), but the mean size of left testis was not significantly changed (P=0.136). In conclusion, 4 month after left side nephrectomy, left side pampiniform vein plexus diameter increased, while there was not significant change in left testis size. Therefore, patients with left side nephrectomy may be proposed to the high risk of varicocele.