To investigate possible changes in anterior segment parameters with the Pentacam in patients taking tamsulosin or doxazosin for benign prostatic hyperplasia. This prospective, cross-sectional study was conducted at Necip Fazil City Hospital, Kahramanmaras, Turkey. Patients included in the study were grouped as follows: 29 patients treated with tamsulosin (group 1), 27 patients treated with doxazosin (group 2), and 40 untreated controls (group 3). Right eyes of each patient were included in the study. All patients underwent examination with the Pentacam under standard dim light conditions and with undilated pupils. Anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) width, central corneal thickness (CCT), corneal volume (CV), and pupil diameter (PD) were recorded. Mean duration of treatments was 2.7 ± 1.2 (1-5) and 2.4 ± 0.9 (1-5) years in groups 1 and 2 (p = 0.276). The ACD, ACV, ACA width, and PD were statistically significantly decreased in groups 1 and 2 when compared to group 3 (p<0.05). There were no statistically significant differences among the groups in mean values of CCT and CV. In this study, decreased ACD, ACV, ACA width, and PD values were detected in tamsulosin and doxazosin groups when compared to controls. These findings should be considered during anterior segment examinations and surgeries.