© Translational Andrology and Urology. All rights reserved. Transl Androl Urol, 2015;4(S1) www.amepc.org/tau of the so-called ‘The second viagra’, e.g., Tadalafil and Vardenafil in 2003. Currently, these 3 kinds of PDE5 inhibitors are most famous and well-known PDE5 inhibitors worldwide. In Korea, another 3 kinds of PDE5 inhibitors, Udenafil (2005), Mirodenafil (2007) and Avanafil (2011) have been developed and 6 kinds of PDE5 inhibitors were used in the competitive market. In last 10 years, the evolution of PDE5 inhibitors competition has changed the dosage concept from on-demand to daily low-dose and applied for other indications beyond ED such as pulmonary hypertension in Sildenafil, and BPH/LUTS in Tadalafil and penile rehabilitation with daily low dose. For the preparations of PDE5 inhibitors, the termination of Korean patent of sildenafil in 2012 released 4 preparations of PDE5 inhibitors, tablet, oro-disposable film, granule and chewable of 60 generic Sildenafil from 49 companies. The orodisposable film and chewable are favorable from patients. In Korea, patent of Cialis will be terminated in near future and the development of generic drugs like Viagra will go in the right way and as expected. The long half-life of Tadalafil enabled the approval for BPH/LUTS with daily low dose usage. In turn, the generic Cialis also will be developed as various preparations including oro-disposable film and as combination with antihypertensive for ED/HT, PDE5 inhibitor with alpha blockers for ED/LUTS and PDE5 inhibitor with antidepressant for ED/PE. The present lecture review the evolution of PDE5 inhibitors from the development of sildenafil citrate in 1998 to combination in 2015, Korea.