Transcription of rRNA, mRNA, and small RNAs in eukaryotes is accomplished by RNA polymerases I, II, and III. Much of the control of transcription occurs at the promoters, where transcriptional regulators can affect the recruitment of polymerases and their accessory factors, the rate at which the polymerases leave the promoter and the rate of transcriptional elongation. At least three levels of control must operate to ensure that regulation of the entire genome is efficiently coordinated in response to the extracellular environment and the cell cycle. There must be mechanisms that permit cells to rapidly increase or reduce the transcription of specific protein-coding genes. There must be an ability to modulate global transcription to adjust for changing levels of nutrients or growth factors, and to accommodate the demands of the cell cycle. Finally, there must be a system to coordinate the relative amounts of rRNA, mRNA, and small RNAs. One factor that is present at promoters used by all three RNA polymerases, and is thus a likely target for all three types of control, is TATA-binding protein (TBP). TBP is associated with a variety of factors that play important roles in both general and gene-specific regulation of gene expression. Early biochemical studies in mammalian, fly, and yeast systems identified three distinct complexes containing TBP, each of which directs transcription at class I, II, or III promoters. The TBP-associated factors that bind to class I, II, and III promoters are called TAFIs, TAFIIs, and TAFIIIs, respectively. There is now evidence that at least five additional factors interact with TBP. Among the eight factors that interact with TBP, four (TAFI, TAFIIs, TAFIIIs, and PTF/SNAPc) function in promoter selection (Fig. 1). The other four (SAGA, Mot1, NC2, and Nots) function together with TAFIIs to regulate expression of protein-coding genes (Fig. 2). All but one of these factors (PTF/SNAPc) is highly conserved among eukaryotes. The factors that interact with TBP in yeast are summarized in Table 1. Here we review our current understanding of the eukaryotic TBP-associated proteins and their roles in regulation of gene expression. We describe evidence that relatively small pools of each of the TBP-associated proteins interact with and regulate a large cellular pool of TBP in yeast, and discuss its implications for genome-wide regulation. The conservation of the TBP-associated proteins suggests that the regulatory mechanisms described here apply to eukaryotes in general. Among the concepts that emerge in this discussion, we note that the TBP-associated regulatory apparatus is more complex than is typically modeled for protein-coding genes, that the means by which TBP is recruited to promoters is not yet well understood, and that there are a surprising number and variety of regulatory factors devoted to repressing TBP function.