In this paper we present the guidelines for the development of an extrasolar planet taxonomy. The discovery of an increasing number of extrasolar planets showing a vast variety of the "planetary parameters",like keplerian orbital elements and also "environmental parameters", like stellar masses, spectral types, etc., prompts the development of a planetary taxonomy. In this work via principal component analysis followed by hierarchical clustering analysis, we report the definition of five robust groups of planets. We discuss the physical relevance of such analysis, which may provide a valid support for disentangling the role of the several physical parameters involved in the planetary formation processes and subsequent evolution. For some clusters, we find statistically significant trends such that, for instance, between the metallicity and the orbital parameters of planets. We also comment on the diversity of extrasolar systems with respect to our own Solar System -by including Jupiter- in this scenario.