The analysis of complex cloud scenes that potentially contain more than one cloud layer in a vertical column is an intriguing problem. In many cases, transmissive cirrus overlies boundary-layer water clouds. When this occurs, our goal is to detect cloud overlap from nighttime MODIS (Moderate Resolution Imaging Spectroradiometer) data. The MODIS imager is on the NASA Terra platform, which is in a polar-orbiting, sun-synchronous orbit at an altitude of 705 km. MODIS spectral bands used in our analyses include 3.8, 8.5, 11, and 12 µ m. We will present results from application of radiative transfer theory that form the basis or our approach. The methodology for the detection of cloud overlap will be highlighted in examples from nighttime MODIS imagery. To support the interpretation of our satellite-based analyses, we will also provide surface-based radar and lidar data collected at the ARM Clouds and Radiation Testbed (CART) Southern Great Plains site in Oklahoma.