<b><i>Purpose:</i></b> To evaluate choroidal thickness in patients with idiopathic choroidal neovascularization. <b><i>Methods:</i></b> The observational case series study included patients who were consecutively diagnosed with idiopathic unilateral choroidal neovascularization as demonstrated by ophthalmoscopy, fluorescein angiography and enhanced depth imaging optical coherence tomography (EDI-OCT). Using EDI-OCT, choroidal thickness was measured at the fovea and at locations in a distance of 500, 1,000 and 1,500 μm temporal and nasal to the fovea. <b><i>Results:</i></b> Mean subfoveal choroidal thickness was significantly (p = 0.002) thicker in the study group than in the control group (357 ± 99 vs. 316 ± 83 μm). In a parallel manner, the differences between the study group and the control group in choroidal thickness were significant for all other measurement points, except for the examination at 1,500 μm nasal to the fovea (p = 0.09). The results remained unchanged after adjusting for axial length and age. <b><i>Conclusions:</i></b> Idiopathic unilateral choroidal neovascularization is associated with a thickening of the choroid.