Pur po se: To study the relationship between keratoconus and axial myopia and also to compare anterior chamber depth, axial length and posterior segment length in normal eyes and keratoconic eyes using ultrasound biometry. Ma te ri al and Met hod: In this study, refraction and ocular biometry in 44 keratoconus eyes and 44 emmetropic eyes were evaluated prospectively. All subjects underwent axial length and anterior chamber depth measurement by ultrasound biometry. Statistical methods were employed to compare the two groups and to ascertain whether any associations exist. Re sults: The axial length was significantly longer in the keratoconic group than in the emmetropic control group in a statistically significant fashion. The mean axial lengths in the keratoconic and emmetropic groups were 23.83±0.72 and 22.81±0.66 mm, respectively (p=0.001). The mean posterior segment length in the keratoconic group was 19.96±0.41 vs. 19.63±0.54 mm in the emmetropic group (p=0.002). The mean keratometry for the keratoconic group correlated with spherical equivalence and visual acuity. Dis cus si on: Keratoconic eyes have on average longer axial lengths and posterior segment lengths than emmetropic eyes. This finding suggests a statistical relationship between keratoconus and axial myopia. (Turk J Ophthalmol 2012; 42: 246-8)