The Ras GTPases are the founding members of large Ras superfamily, which constitutes more than 150 of these important class of enzymes. These GTPases function as GDP-GTP-regulated binary switches that control many fundamental cellular processes. There are a number of GTPases that have been identified recently, which do not confine to this prototype termed as "atypical GTPases" but have proved to play a remarkable role in vital cellular functions. In this review, we provide an overview of the crucial physiological functions mediated by RGK and Centaurin class of multi domain atypical GTPases. Moreover, the recently available atypical GTPase structures of the two families, regulation, physiological functions and their critical roles in various diseases will be discussed. In summary, this review will highlight the emerging atypical GTPase family which allows us to understand novel regulatory mechanisms and thus providing new avenues for drug discovery programs.