High-performance low-voltage flash memories based on organic floating-gate field-effect transistors are prepared by a solution process for the first time. Transistors with a high-mobility n-type polymer semiconductor, poly{[N,N(')-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)}, and a high-k polymer gate dielectric, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (k ≈ 60), are successfully fabricated on flexible substrates. A thin layer of Au nanoparticles is embedded in the gate dielectric, which can store injected charge from the channel and result in a memory effect. The organic memories demonstrate high carrier mobilities (>0.3 cm(2)/(V s)), low program/erase voltages (±6 V), little degradation after 10(5) program/erase cycles, and good retention after 10(5) s, which suggest great promise in the application of nonvolatile memories in flexible electronics.