The past year has seen dramatic changes in our understanding of ribosome synthesis, fuelled largely by advances in proteomic analysis. It is now possible to outline the pathway of ribosome assembly, which is highly dynamic and involves a remarkable separation of the factors involved in the synthesis of the 40S and 60S ribosomal subunits. Around 140 identified, non-ribosomal proteins are currently implicated in post-transcriptional ribosome synthesis in yeast.