Chromatin structure has a pivotal role in the regulation of gene expression. Transcriptional activation or the repression of a gene require the recruitment of multiple chromatin remodeling complexes. Chromatin remodeling complexes modulate the higher order structure of chromatin, facilitate or hinder the binding of transcription factors, and aid in or prevent the establishment of a transcriptional preinitiation complex. Two types of chromatin remodeling complexes have been extensively studied--ATP-dependent chromatin remodeling complexes and histone-modifying enzymes--which include histone acetyltransferases, histone deacetylases, and histone kinases. Transcriptional activators and repressors are responsible for recruitment of one or more of these large, multisubunit chromatin remodeling complexes. In this review, the features of the chromatin remodeling complexes and the modes of their recruitment are presented.