Transcriptomics, the analysis of the complement of mRNAs transcribed from a cell's genome, currently focuses mainly on mature, processed mRNAs. However, posttranscriptional processing of primary transcripts can significantly affect both the quantity and the structure of the mature mRNAs and therefore of the protein products. Recently, the development of an intron-specific microarray has permitted a preliminary analysis of the splicing of all intron-containing transcripts in Saccharomyces cerevisiae. Here, we discuss the findings and what might be learned from this kind of approach.