The powder‐metallurgical process for the preparation of filamentary Nb3Sn and V3Ga microcomposites is described and compared to alternative processing techniques. Investigations of the thermal stability of the submicron size filamentary structure show that the thickness of the ribbonlike filaments should be in the range between 0.1 and 1 &mgr;m for a typical wire diameter of 0.2–0.4 mm to avoid a spheroidization of the filaments during the diffusion treatment. The superconducting properties are comparable to the optimized values of other techniques. Overall critical current densitiesJcof a Cu‐30 wt. % Nb+Sn composite wire amount to 109and 1.6×108A/m2at fields of 10 and 15 T, respectively, whereas values up to 4×108A/m2at 16 T are observed for Cu‐30 wt. % V+Ga composites. The mechanical behavior such as tensile strength, and the dependence of the superconducting current carrying capability on tensile stress and strain show a favorable behavior in light of a technical application.