Purpose: This study aimed to compare the effectiveness of pulsatile flushing and continuous flushing in preventing catheter occlusion among patients with peripherally inserted central catheters (PICCs). Methods: A quasi-experimental study with a nonequivalent control group and non-synchronized design was conducted at the medical-surgical ward of a university hospital. A total of 80 patients who underwent PICC insertion between October 2024 and July 2025 were enrolled. From the day after catheter insertion, participants were assigned to the control group (continuous flushing) or the experimental group (pulsatile flushing), and each group received daily flushing for seven consecutive days. Catheter patency was assessed every day, and the intervention was discontinued when partial or complete occlusion was identified. No dropout occurred during the study period. Data were analyzed using SPSS (version XX) with descriptive statistics and χ2 or Fisher’s exact tests, and the level of statistical significance was set at p<.05. Results: The experimental group had no complete occlusion (0.0%), whereas 4 cases (10.0%) occurred in the control group. Partial occlusion was observed in 29 cases (72.5%) in the control group and 14 cases (35.0%) in the experimental group. A significant difference was found between the two groups (p=.001). Conclusion: Pulsatile flushing is more effective than continuous flushing for maintaining PICC patency and may be recommended as an evidence-based nursing intervention.