A polydimethylsiloxane (PDMS) light-guide plate (LGP) having micropatterns with an inverse-trapezoidal cross section was developed for a sheet-less LCD backlight unit (BLU). The micropatterned PDMS LGP was fabricated by backside 3-D diffuser lithography followed by two consecutive PDMS replication processes: photoresist-to-PDMS and PDMS-to-PDMS replications. The fabricated LGP showed an average luminance of 2878 nits and a uniformity of 73.3% in a 2-in. backlight module with four side-view 0.85-cd LEDs. It also could feasibly be applied to a light source for flexible displays owing to the flexible characteristic of the PDMS itself.