Wave elevation on large cylinders due to irregular waves have been calculated based on the McCamy and Fuchs linear diffraction theory and on the principle of superposition. Experiments have been conducted in the Hydraulic Engineering Laboratory, Indian Institute of Technology, Madras, to examine the wave elevation excited by wind-generated irregular waves on circular cylinders of large diameter. The wave elevation around the cylinders at representative locations were measured and compared with calculated wave elevations. The spectral density functions computed from wave elevation time series measured in the laboratory were compared with calculated time elevation spectral densities on the cylinder. © 1988 by ASME.