In this communication, cross-polarized (XP) radiation of cylindrical dielectric resonator antenna (CDRA) has been investigated with a view to identify the source of the same. The study starts with a conjecture, which has been established through a systematic study using simulated results. The inference has been verified experimentally with the help of a set of prototypes. HEM21δ has been identified as the XP generating mode and a small metallic grounded post of circular cross section has been conceived to perturb the same to prove the conjecture. This insight has been extended to demonstrate a practical application indicating a possibility of achieving up to 8-10-dB suppression in XP radiation from a CDRA. © 1963-2012 IEEE.