In the study described herein, CrTaWN x thin films were deposited on Si and 304 stainless-steel (SUS304) substrates through magnetron co-sputtering using CrW and Ta targets. The nitrogen flow ratio ( f N2 = [N 2/(N 2 + Ar)]) was adjusted to 0.05, 0.2, 0.4, and 0.5 to fabricate CrTaWN x films with various N contents. The CrTaWN x films prepared at a low f N2 of 0.05 exhibited a low stoichiometric ratio x of 0.16 and a nanocrystalline structure. In contrast, the CrTaWN x films fabricated at an f N2 of 0.2–0.5 exhibited x values of 0.42–0.62 and formed a face-centered cubic phase. The nanocrystalline (Cr 0.34Ta 0.20W 0.46)N 0.16 film exhibited mechanical properties and wear resistances that were inferior to those of the crystalline CrTaWN x thin films. A (Cr 0.38Ta 0.15W 0.47)N 0.55 film exhibited a hardness of 25.2 GPa, an elastic modulus of 289 GPa, and a low wear rate of 0.51 × 10 −5 mm 3/Nm.