With the new techniques of cataract surgery visual success has increased and it became necessary to foresee undesirable postoperative results regarding visual acuity. Purpose: To verify the role of ocular ultrasonography in the preoperative evaluation of patients with mature cataract searching for posterior segment pathologies that may affect surgical results, their prevalence and the main associated risk factors. Methods: A retrospective study was performed analyzing records of 262 patients indicated for ocular ultrasonography because the presence of mature cataract, thus preventing fundoscopic evaluation of the posterior segment. It was also tried to associate the presence of those changes with sex, age, race, history of ocular trauma, systemic and ocular diseases and the presence of cataract in the contralateral eye. Results: Ecographic changes were found in 24.8% of the examinations performed between 1996 and 2001, of which retinal detachment and vitreous condensations were the most common, with 9.9% of the findings for each. Conclusions: Among the risk factors pointed out as predisposing to findings in ocular ultrasonography, uveitis was the only statistically significant element. It was not possible to correlate positively the described posterior segment pathology to ocular trauma using obtained data.6713336Anteb II, Y., Blumenthal, E.Z., Zamir, E., Waindim, P., The role of preoperative ultrasonography for patients with dense cataract: A retrospective study of 509 cases (1998) Ophthalmic Surg Lasers, 29, pp. 114-118Datiles, M.B., Lasa, M.S., Freidlin, V., A longitudinal study of cortical cataracts using retroillumination photographs (1996) Curr Eye Res, 15, pp. 53-61Barret, B.T., Davison, P.A., Eustace, P., Clinical comparison of three techniques for evaluating visual function behind cataract (1995) Eye, 9 (PART. 6), pp. 722-727Haile, M., Mengistu, Z., B-scan ultrasonography in ophthalmic diseases (1996) East Afr Med, 73, pp. 703-707Hurst, M.A., Douthwaite, W.A., Assessing vision behind cataract: A review of methods (1993) Optom Vis Sci, 70, pp. 903-913Fielding, J.A., Imaging the eye with ultrasound (1992) Br J Hosp Med, 47, pp. 805-815Conover, W.J., (1971) Practical Nonparametric Statistics, , New York: John Wiley & SonsFleis, J.L., (1981) Statistical Methods for Rates and Proportions, , 2aed. New YorkJohn Wiley &ampSonsHosmer, D.W., Lemeshow, S., (1988) Applied Logistic Regression, , New York: John Wiley & SonsCorrêa, Z.M.S., Goldhardt, R., Marcon, A.S., Marcon, I.M., Achados ecográficos em pacientes com catarata total (2002) Arq Bras Oftalmol, 65, pp. 609-613