Nowadays, an increasing number of handheld laser scanners with integrated Real Time Kinematic-Global Navigation Satellite System (RTK-GNSS) become available on the market. However, a method for determining their absolute trajectory accuracy remains difficult until now. Therefore, this study examines the absolute trajectory accuracy of a RTK-GNSS integrated handheld laser scanner under outdoor conditions. For this purpose, eight field measurements in different surrounding conditions were conducted and compared with a reference trajectory recorded using a total station in automatic target recognition (ATR) mode. The results of the field measurements demonstrate that the RTK-Personal Laser Scanner (PLS) achieves the manufacturer's specified absolute accuracy of 5 centimeters Root Mean Square Error (RMSE) in both the horizontal and vertical directions, despite slight shading caused through surrounding buildings or tree canopies. Larger deviations appeared particularly in areas with heavier shading from vegetation, for loop-free trajectories, and in environments with few features for Simultaneous Localization And Mapping (SLAM) optimization. In contrast, scans in structurally varied environments with clear geometric features, such as tree trunks, resulted in smaller deviations from the target trajectory, even though the scans were not taken under optimal GNSS conditions due to slight shading. Accordingly, while RTK-GNSS integration can enable centimeter-accurate positioning without any ground control points (GCP), factors such as route planning and environmental conditions still appear to be crucial to the absolute trajectory accuracy.