A universal method for the rapid isolation of all known classes of functional small RNAs. Diverse classes of regulatory small (s)RNAs operate via ARGONAUTE-family proteins within RNA-induced-silencing-complexes (RISCs). Based on the conserved biochemical properties intrinsic to all ARGONAUTEs, we have developed a universal, 15-min benchtop extraction procedure allowing simultaneous purification of all classes of RISC-associated sRNAs, without prior knowledge of the sample’s -intrinsic ARGONAUTE repertoires. Optimized as a user-friendly kit, the method –coined “TraPR” for Trans-kingdom, rapid, affordable Purification of RISCs– operates irrespectively of the organism, tissue, cell type or bio-fluid of interest, and scales to minute amounts of input material. The method is highly suited for direct sRNA profiling, with TraPR-generated libraries outperforming those obtained via gold-standard procedures that require immunoprecipitations and/or lengthy polyacrylamide gel excisions. TraPR considerably improves the quality and consistency of sRNA sample preparation including from notoriously difficult-to-handle tissues/bio-fluids such as starchy storage roots and mammalian plasma, and regardless of RNA contaminants or samples’ RNA-degradation status.