The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Aqua platform has 9 spectral bands with center wavelengths from 412nm to 870nm that are used to produce the standard ocean color data products. Ocean scenes usually contain high contrast due to the presence of bright clouds over dark water. The MODIS has been characterized for straylight effects prelaunch. In this paper, we derive Point-Spread Functions for the MODIS Aqua ocean bands based on the prelaunch Near-Field Response measurements. We use Harvey-Shack coefficients derived by the system vendor Santa Barbara Remote Sensing. The crucial step in the derivation of the Point-Spread Function is the normalization of the Harvey-Shack coefficients relative to the center pixel. The straylight contamination of ocean scenes is evaluated based on artificial test scenes. Furthermore, the dependence of top-of-atmosphere radiances and ocean color products on proximity to a cloud is analyzed, and a straylight correction algorithm is proposed.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.