Aptamers are short synthetic oligonucleotides that specifi cally bind to various molecular targets with high affi nity and selectivity. Aptamers have found two main applications in bacteriology, diagnosis in various sensing applications and riboswitches. Rickettsiosis are diseases caused by rickettsias 'sensu lato' including spotted fever, typhus, anaplasmosis, ehrlichiosis, bartonellosis and Q fever. Traditional methodologies for the diagnosis of diseases associated with rickettsias 'sensu lato' are based on serological testing, bacterial cultures and molecular assays. However, an increasing number of novel technologies, including aptamer-based diagnostic sensors, are now on the horizon, opening up possibilities for earlier diagnosis and more sensitive assays. Th is perspective looks at the contribution of aptamers to rickettsias 'sensu lato' diagnosis, providing information on the 'state of the art' in this emerging fi eld..