Progress in the X-ray crystallography of bacterial ribosomes or their subunits has become so rapid that we are now seeing the publication of near-complete atomic structures for both the 16S and 23S rRNA molecules from thermophilic and halophilic ribosomes. At the same time, cryo-electron microscopic studies on Escherichia coli ribosomes in various functional states are now yielding structures at single figure resolution and still improving. Combined with all of the available biochemical information, these new results will generate a quantum leap in our understanding of the structures and mechanisms involved in protein biosynthesis.