Optical coherence tomography (OCT), originally developed for the biomedicine sector, was found to be a powerful tool for the non-destructive testing and characterization of polymeric matrix composites about two decades ago. Initially, those composites consisted out of duroplastic matrix materials exclusively. Recently, there is a strong trend to replace these duroplastic polymers by thermoplastics and therefore the question concerning appropriate and reliable quality assessment arose. In this paper, OCT is evaluated as a technique to detect common quality defects occurring during the continuous production of thermoplastic glass-fiber reinforced UD-tapes. Stationary offline measurements with a Thorlabs Telesto spectral domain OCT system, that works at a wavelength of 1300 nm and a sampling rate of 28 kHz, were carried out to investigate typical defects such as filled/unfilled gaps, fiber breakages, dry fiber regions, bubbles, and edge defects. The investigated tape samples consist out of glass-fibers and a thermoplastic polycarbonate matrix. Edge defects, dry regions, fiber breakages and empty gaps were successfully detected using OCT. More challenging was the detection of polymeric filled gaps and small bubbles on the tape surface . Our study showed that OCT allows non-destructive, high resolution defect detection in glass-fiber reinforced UD-tapes. Furthermore, as an outlook, OCT has a very high potential to deal as a powerful, fast, and most important non-destructive technique for the inline quality assessment of the continuous production of thermoplastic glass-fiber reinforced UD-tapes. Keywords: optical coherence tomography, thermoplastic UD-tapes, unidirectional glass-fiber reinforced thermoplastics, composites.