This article provides a flexible workflow for the analysis of chromatin immunoprecipitation data (ChIP-chip) that covers issues from quality control, probe sequence remapping, data preprocessing/normalization, visualization, and high-level analysis like peak finding. It emphasizes the peculiarities of single-color Affymetrix arrays, but it is flexible enough to be also amenable to other array platforms. The article is accompanied by extensive code implementing each of the analysis steps.