PURPOSE:To evaluate the structure of the endopelvic fascia in prostates of different weights.METHODS: We studied 10 patients with BPH (prostates>90g); 10 patients with prostate adenocarcinoma (PAC) (prostates<60g) and five young male cadavers (control group). During the surgery a small sample of endopelvic fascia was obtained. We analyzed elastic fibers, collagen and smooth muscle. The stereological analysis was done with the Image Pro and Image J programs. Means were statistically compared using the one-way ANOVA with the Bonferroni test and a p<0.05 was considered statistically significant.RESULTS:The mean of the prostate weight was 122 g in BPH patients, 53.1g in PAC patients and 18.6g in control group. Quantitative analysis documented that there are no differences (p=0.19) in Vv of elastic fibers and in Vv of type III collagen (p=0.88) between the three groups. There was a significant difference (p=0<0.0001) in the quantification of SMC in patients with prostates >90g (mean=9.61%) when compared to patients with prostates <60g (mean=17.92%) and with the control group (mean=33.35%).CONCLUSION:There are differences in endopelvic fascia structure in prostates>90g, which can be an additional factor for pre-operatory evaluation of radical prostatectomy.