Potato virus Y (PVY) is the type member of the genus Potyvirus, which includes some of the most destructive plant viruses. PVY has been placed on a Top 5 list of scientifically and economically important plant viruses, affecting potato, tomato, tobacco, pepper as well as ornamentals and weeds. PVY virions are assembled of a positive sense single stranded RNA, enveloped with approximately 2000 copies of a coat protein (CP) to form flexuous filaments 740 nm in length and 12 nm in diameter. Expression of recombinant CP in bacteria results in formation of self-assembled flexuous filaments called virus like particles (VLPs), which are devoid of viral RNA and thus non-infectious. In my talk I will show our recent results on near-atomic cryo-EM structures of both, PVY virions (‘bad guys’) and VLPs (‘good guys’), revealing unique structural features of PVY and significant differences between the two types of filaments. Furthermore, I will also discuss the potential of VLPs for use in (bio)technology.