Recent progress in global sequence and microarray data analysis has revealed the increasing complexity of the human transcriptome. Alternative splicing generates a huge diversity of transcript variants and disruption of splicing regulatory networks is emerging as an important contributor to various diseases, including cancer. Current efforts to establish the dynamic repertoire of transcripts that are generated in health and disease are showing that many cancer-associated alternative-splicing events occur in the absence of mutations in the affected genes. A growing body of evidence reveals changes in splicing-factor expression that correlate with cancer development, progression and response to therapy. Here, we discuss how recent links between cancer and altered expression of proteins implicated in splicing regulation are bringing the splicing machinery to the fore as a potential target for anticancer treatment.