PURPOSE: Lateral cystourethrography is a radiological method used in the diagnosis and prediction of the degree of stress urinary incontinence. The aim of this study was to evaluate the efficiency of lateral cystourethrography in women with stress urinary incontinence. MATERIALS AND METHODS: In this retrospective study, a total of 76 women who underwent both cystourethrography and urodynamic study were included. The proximal urethral support was evaluated by lateral cystourethrography at rest and during voiding, with the images anatomically superimposed to measure the degree of bladder base descent and the posterior urethro-vesical angle (PUV angle). The urethral diameter was measured at 1cm below the bladder neck. Urodynamic assessments, included valsalva leak point pressure (VLPP), maximal urethral closing pressure (MUCP) and functional urethral length, were compared with the parameters of the cystourethrography. RESULTS: There was a significant correlation between the VLPP and the urethral diameter (p<0.05) only. Other parameters from the two methods showed no significant correlations. When the patients were divided into three subgroups, according to their VLPP (<60, 60-90, >90cmH2O), and into two subgroups, according to their MUCP (<25, >25cmH2O), the mean values of bladder base descent and PUV angle among the subgroups showed no significant correlation. CONCLUSIONS: In the current study, the lateral cystourethrography is suggested to not be appropriate for the diagnosis and prediction of stress urinary incontinence.