The distinctive length and morphology characteristics of thermomechanical produced wood fibers make it a promising candidate for the utilization in polymer composites. However, due to the low bulk density of these fibers, the feeding into the compounding process (i.e., extruders) is quite challenging. In this study, a novel simultaneous defibration and compounding process are conducted in order to solve the feed‐in problem of thermomechanical fibers. A disc‐refiner was used to defibrate wood chips to fibers and compound the fibers with neat polymer granulates in one process step. After the process, the material showed typically thermomechanical fibers with chopped polymer particles which were inseparably attached to the fiber. The observed mechanical properties of the composites were slightly lower than some literature values. With field emission scanning electron microscopy and X‐ray microtomography analysis, voids and a polymer enriched surface were found influencing the composites performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45859.