A brief review of recent advances in the understanding of human rhinovirus molecular biology is presented. The importance of recent findings on the elucidation of serotypic diversity and their implications for the viral host-cell receptor site are emphasized. An introduction to the genome structure and to the pathway of gene expression in rhinoviruses leads on to a discussion of the crystal structure of human rhinovirus 14 (HRV14) and the antibody-inducing regions on the surface of the capsid. Evidence from these experiments indicates that four sites on HRV14 are responsible for inducing neutralizing antibodies. Amino-acid sequence comparisons reveal that these sites are different in other serotypes, strengthening the view that the sequences of these regions are fundamental in determining and defining rhinovirus serotypes. The crystal structure of HRV14 points to a depression in the viral capsid as being the site of binding to the host-cell receptor; however, residues involved in binding cannot yet be identified.