Retinal degeneration‐1 (rd1) mice are animal models of retinitis pigmentosa, a blinding disease caused by photoreceptor cell degeneration. This study aims to determine magnetic resonance imaging (MRI) changes in retinas of 1‐ and 3‐month‐old rd1 mice. Apparent diffusion coefficient in retina was measured using diffusion MRI. The blood‐retinal barrier leakage was evaluated using gadolinium‐diethylenetriaminepentaacetic acid‐enhanced T₁‐weighted MRI before and after systemic gadolinium‐diethylenetriaminepentaacetic acid injection. Photoreceptor degeneration in rd1 retina was apparent by decreased retinal thickness and loss of water diffusion anisotropy in both 1‐ and 3‐month‐old rd1 mice. Furthermore, statistically significant increase of mean retinal apparent diffusion coefficient and gadolinium‐diethylenetriaminepentaacetic acid‐enhanced T₁‐weighted MRI signals were observed in 3‐month‐old rd1 mice comparing with age‐matched wild‐type mice. Together, these data suggest that MRI parameter changes can signature common pathological changes in photoreceptor‐degenerated eyes, particularly blood‐retinal barrier leakage‐induced retinal edema. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.