<p>This study investigated impact damage characterization of reinforced thermoplastic pipes (RTP) using X-ray computed tomography (CT) scan and phased array ultrasonic testing (PAUT) techniques. Two types of RTP samples, namely the standard (ST) and gas-tight (GT) types, were impacted using a drop-weight tower. The X-ray CT scan revealed detailed cross-sectional views of damages, including fiber breakage, matrix degradation, and aluminum layer damage. With the implementation of time-corrected gain method in a zero-degree configuration, PAUT demonstrated damage detection capabilities comparable to the CT scan technique by employing various frequencies and focusing techniques. However, it was challenging to accurately assess the extent of damage in the GT type due to the presence of the aluminum layer. While higher-frequency PAUT transducers improved sizing accuracy for the ST type, sizing damages in the GT type remained challenging. Implementing a focusing technique revealed ultrasonic B-scan cross-sectional images of damage closely resembling those from CT scans, offering insights into through-thickness damage morphology. This research showed that the results from the ultrasonic wave-based technique were in good agreement with those from the X-ray imaging-based technique.</p>